LUMMUS, Justice.

 On November 28, 1942, and for about nine years before that day, a corporation named New Cocoanut Grove, Inc., maintained and operated a 'night club' in Boston, having an entrance at 17 Piedmont Street, for the furnishing to the public for compensation of food, drink and entertainment, consisting of orchestra and band music, singing and dancing.  It employed about eighty persons.  The corporation, its officers and employees, and its business, were completely dominated by the defendant Barnett Welansky, who is called in this opinion simply the defendant, [p. 387] since his codefendants were acquitted by the jury. . . .

 The defendant was accustomed to spend his evenings at the night club, inspecting the premises and superintending the business.  On November 16, 1942, he became suddenly ill, and was carried to a hospital, where he was in bed for three weeks and remained until discharged on December 11, 1942.  During his stay at the hospital, although employees visited him there, he did not concern himself with the night club, because, as he testified, he 'knew it would be all right' and that 'the same system * * * [he] had would continue' during his absence.  There is no evidence of any act, omission or condition at the night club on November 28, 1942 (apart from the lighting of a match hereinafter described), that was not within the usual and regular practice during the time before the defendant was taken ill when he was at the night club nearly every evening.  While the defendant was at the hospital, his brother James Welansky and an employee named Jacob Goldfine, who were made codefendants, assumed some of the defendant's duties at the night club, but made no change in methods. Under these circumstances the defendant was not entitled to a verdict of not guilty on the ground that any acts or omissions on the evening of November 28, 1942, were the transitory and unauthorized acts or omissions of servants or other persons, for which the defendant could not be held criminally responsible.

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 We now come to the story of the fire.  A little after ten o'clock on the evening of Saturday, November 28, 1942, the night club was well filled with a crowd of patrons.  It was during the busiest season of the year.  An important football game in the afternoon had attracted many visitors to Boston.  Witnesses were rightly permitted to testify that the dance floor had from eighty to one hundred persons on it, and that it was 'very crowded.'  Beverley v. Boston Elevated Railway, 194 Mass. 450, 457, 80 N.E. 507.  Witnesses were rightly permitted to give their estimates, derived from their observations, of the number of patrons in various parts of the night club.  Upon the evidence it could have been found that at that time there were from two hundred fifty to four hundred persons in the Melody Lounge, from four hundred [p. 392] to five hundred in the main dining room and the Caricature Bar, and two hundred fifty in the Cocktail Lounge.  Yet it could have been found that the crowd was no larger than it had been on other Saturday evenings before the defendant was taken ill, and that there had been larger crowds at earlier times.  There were about seventy tables in the dining room, each seating from two to eight persons.  There was testimony that all but two were taken.  Many persons were standing in various rooms.  The defendant testified that the reasonable capacity of the night club, exclusive of the new Cocktail Lounge, was six hundred fifty patrons.  He never saw the new Cocktail Lounge with the furniture installed, but it was planned to accommodate from one hundred to one hundred twenty-five patrons.

 A bartender in the Melody Lounge noticed that an electric light bulb which was in or near the cocoanut husks of an artificial palm tree in the corner had been turned off and that the corner was dark.  He directed a sixteen year old bar boy who was waiting on customers at the tables to cause the bulb to be lighted.  A soldier sitting with other persons near the light told the bar boy to leave it unlighted.  But the bar boy got a stool, lighted a match in order to see the bulb, turned the bulb in its socket, and thus lighted it.  The bar boy blew the match out, and started to walk away.  Apparently the flame of the match had ignited the palm tree and that had speedily ignited the low cloth ceiling near it, for both flamed up almost instantly.  The fire spread with great rapidity across the upper part of the room, causing much heat.  The crowd in the Melody Lounge rushed up the stairs, but the fire preceded them.  People got on fire while on the stairway.  The fire spread with great speed across the foyer and into the Caricature Bar and the main dining room, and thence into the Cocktail Lounge.  Soon after the fire started the lights in the night club went out.  The smoke had a peculiar odor.  The crowd were panic stricken, and rushed and pushed in every direction through the night club, screaming, and overturning tables and chairs in their attempts to escape.

 The door at the head of the Melody Lounge stairway [p. 393] was not opened until firemen broke it down from outside with an axe and found it locked by a key lock, so that the panic bar could not operate.  Two dead bodies were found close to it, and a pile of bodies about seven feet from it.  The door in the vestibule of the office did not become open, and was barred by the clothing rack.  The revolving door soon jammed, but was burst out by the pressure of the crowd.  The head waiter and another waiter tried to get open the panic doors from the main dining room to Shawmut Street, and succeeded after some difficulty.  The other two doors to Shawmut Street were locked, and were opened by force from outside by firemen and others.  Some patrons escaped through them, but many dead bodies were piled up inside them.  A considerable number of patrons escaped through the Broadway door, but many died just inside that door.  Some employees, and a great number of patrons, died in the fire.  Others were taken out of the building with fatal burns and injuries from smoke, and died within a few days.

 I.   The pleadings, verdicts, and judgments.

 The defendant, his brother James Welansky, and Jacob Goldfine, were indicted for manslaughter . . . .

 . . . . [T]he counts . . . alleged in substance that the New Cocoanut Grove, Inc., a corporation, did for a period of time prior to and including November 28, 1942, maintain and operate a night club, to which it invited members of the general public; that it was under a legal duty to its invitees to use reasonable care to keep its premises safe for their use; that the three persons indicted were authorized by the corporation to maintain, control, operate, construct, alter, supervise, and manage its premises in its behalf; that said three persons accepted the responsibility for such acts, and were therefore under a duty to its invitees to use such reasonable care; that in reckless disregard of such duty to one (naming the victim) who was lawfully upon said premises pursuant to such invitation to the general public, and of the probable harmful consequences to him of their failure to perform said duty, they and each of them did 'wilfully, wantonly and recklessly neglect and fail to fulfil their said legal duty and obligation to the said' victim, by reason whereof he on November 28, 1942, received a mortal injury, as a result of which on that day he died.

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 The defendant was found guilty [and] sentenced to imprisonment in the State prison upon each count for a term of not less than twelve years and not more than fifteen years, the first day of said term to be in solitary confinement and the residue at hard labor . . . .

 II.   The principles governing liability.

 The Commonwealth disclaimed any contention that the defendant intentionally killed or injured the persons named in the indictments as victims.  It based its case on involuntary [p. 397] manslaughter through wanton or reckless conduct. . . .

 Usually wanton or reckless conduct consists of an affirmative act, like driving an automobile or discharging a firearm, in disregard of probable harmful consequences to another.  But where as in the present case there is a duty of care for the safety of business visitors invited to premises which the defendant controls, wanton or reckless conduct may consist of intentional failure to take such care in disregard of the probable harmful consequences to them or of their right to care. . . . Am. Law Inst. Restatement:  Torts, § 500 . . . .

 To define wanton or reckless conduct so as to distinguish it clearly from negligence and gross negligence is not easy.  Banks v. Braman, 188 Mass. 367, 370, 74 N.E. 594; Commonwealth v. Arone, 265 Mass. 128, 132, 163 N.E. 758.  Sometimes the word 'wilful' is prefaced to the words 'wanton' and 'reckless' in expressing the concept.  That only blurs it.  Wilful means intentional.  In the phrase 'wilful, wanton or reckless conduct,' if 'wilful' modifies 'conduct' it introduces [p. 398] something different from wanton or reckless conduct, even though the legal result is the same.  Wilfully causing harm is a wrong, but a different wrong from wantonly or recklessly causing harm.  If 'wilful' modifies 'wanton or reckless conduct' its use is accurate. What must be intended is the conduct, not the resulting harm.  Altman v. Aronson, 231 Mass. 588, 592, 121 N.E. 505, 4 A.L.R. 1185; Banks v. Braman, 188 Mass. 367, 369, 74 N.E. 594.  The words 'wanton' and 'reckless' are practically synonymous in this connection, although the word 'wanton' may contain a suggestion of arrogance or insolence or heartlessness that is lacking in the word 'reckless.'  But intentional conduct to which either word applies is followed by the same legal consequences as though both words applied.

 The standard of wanton or reckless conduct is at once subjective and objective, as has been recognized ever since Commonwealth v. Pierce, 138 Mass. 165, 52 Am.Rep. 264.  Knowing facts that would cause a reasonable man to know the danger is equivalent to knowing the danger. . . . Am.Law Inst. Restatement:  Torts, § 500, and also comments c and f. . . . The judge charged the jury correctly when he said, 'To constitute wanton or reckless conduct, as distinguished from mere negligence, grave danger to others must have been apparent and the defendant must have chosen to run the risk rather than alter his conduct so as to avoid the act or omission which caused the harm.  If the grave danger was in fact realized by the defendant, his subsequent voluntary act or omission which caused the harm amounts to wanton or reckless conduct, no matter whether the ordinary man would have realized the gravity of the danger or not.  But even if a particular defendant is so stupid [or] so heedless * * * that in fact he did not realize the grave danger, he cannot escape the imputation of wanton or reckless conduct in his dangerous act or omission, if an ordinary normal [p. 399] man under the same circumstances would have realized the gravity of the danger.  A man may be reckless within the meaning of the law although he himself thought he was careful.'

 The essence of wanton or reckless conduct is intentional conduct, by way either of commission or of omission where there is a duty to act, which conduct involves a high degree of likelihood that substantial harm will result to another.  Am.Law Inst. Restatement:  Torts, § 500; LeSaint v. Weston, 301 Mass. 136, 138, 16 N.E.2d 631.  Wanton or reckless conduct amounts to what has been variously described as indifference to or disregard of probable consequences to that other . . . .

 The words 'wanton' and 'reckless' are thus not merely rhetorical or vituperative expressions used instead of negligent or grossly negligent.  They express a difference in the degree of risk and in the voluntary taking of risk so marked, as compared with negligence, as to amount substantially and in the eyes of the law to a difference in kind. . . . Am.Law Inst.Restatement:  Torts, § 500, comment g.  For many years this court has been careful to preserve the distinction between negligence and gross negligence, on the one hand, and wanton or reckless conduct on the other. . . .  In pleadings as well as in statutes the rule is that 'negligence and willful and wanton conduct are so different in kind that words properly descriptive of the one commonly exclude the other.' . . . .

 Notwithstanding language used commonly in earlier cases, and occasionally in later ones, [n. 3] it is now clear in this Commonwealth that at common law conduct does not become criminal until it passes the borders of negligence and gross negligence and enters into the domain of wanton or reckless conduct.  There is in Massachusetts at common law no such thing as 'criminal negligence.' . . .
 

3.  In early cases what is now known as wanton or reckless conduct was variously described as wilful negligence, wanton negligence, gross negligence, and culpable negligence . . . .  So in criminal cases what was necessary to make conduct criminal was often so described.  The expression 'criminal negligence' was often used.  But it seems that what we now know as wanton or reckless conduct was in fact required.  The terminology, not the law, is what has changed. . . . At least one statute purports to impose criminal liability for 'gross negligence.'  G.L. (Ter.Ed.) c. 265, § 30.  Whether that expression really means wanton or reckless conduct has not been decided.
In other jurisdictions a variety of similar expressions has been used in describing conduct that will create criminal liability.  But in many of them the substantial equivalent of wanton or reckless conduct is required. . . .

 To convict the defendant of manslaughter, the Commonwealth was not required to prove that he caused the fire by some wanton or reckless conduct.  Fire in a place of public resort is an ever present danger.  It was enough to prove that death resulted from his wanton or reckless disregard of the safety of patrons in the event of fire from any cause.

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  The Commonwealth was properly allowed to show that an exit from the Cocktail Lounge to Shawmut Street and fire doors in the Cocktail Lounge and between that and the older part of the premises, called for by the plans that were approved by the building department of the city of Boston under St.1907, c. 550, § 12, as amended, had not been provided when the defendant last had knowledge of the premises on November 16, 1942, although he planned to open the Cocktail Lounge the next day; that the mode of construction of the Cocktail Lounge indicated that he did not intend to provide either; and that they had not been provided at the time of the fire.  As planned, the fire doors were to be held open by fusible plugs that would melt and allow the doors to close automatically in case of fire.  They and the exits might have afforded some protection to persons in the Cocktail Lounge.  The violation of such a statute is not negligence per se but sometimes is evidence of negligence. . . . Standing by itself, it would not warrant a finding of wanton or reckless conduct. . . . Am.Law Inst. Restatement:  Torts, § 500, comment e.  But it might be considered with other evidence.  There was no error in its admission. . . .

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 Judgments affirmed.