Outside the club, Sessa said, Muller argued with the bouncers and others on the street, and someone stabbed him in the chest.

"(Muller) had some words with the bouncer, and he had some words with some other people outside on the street," Sessa said. "Next thing you know, he's dead."

The police do not know who killed Muller, Sessa said. There were no surveillance cameras trained on the scene and no suspects have been identified.

Attempts to reach representatives of the club and members of Muller's family by telephone were unsuccessful.

The stabbing comes at a time when New York clubs are facing increased scrutiny due to a series of high-profile crimes. Earlier this year, the City Council approved a measure requiring security cameras to be stationed at nightclub doors.

The city has looked at ways to curb nightclub violence since last year, after 24-year-old graduate student Imette St. Guillen was kidnapped, raped and murdered after a night out with friends. A bouncer at the bar where she was last seen has been charged in her death.

Four months later, 18-year-old Harrington Park resident Jennifer Moore was beaten and strangled after leaving the Guest House, a Chelsea club.

Another bouncer was arrested last year after the police say he went on a shooting rampage outside another Chelsea club, killing one man and wounding several others. And in February, a fight at another Chelsea club ended with one patron falling down an elevator shaft to his death.