Rapper Troy Ave was one of four people shot in a third-floor green room at the venue Irving Plaza Wednesday night, before a T.I. performance.

One man died from his injuries.

At 10:15 p.m. Wednesday, the rapper T.I. was about to take the stage at the 1,025-person ballroom-style music venue when the shooting began in the green room.

The NYPD said it has recovered “pretty good” video images of the shooting. Ballistics were recovered from the green room area, indicating a 9 mm handgun was used.

The gunman and the victims were all credentialed guests with access to the VIP/green room area. There does not appear to have been any screening at the VIP area, which was filled with performers, their entourages and guests. According to police, most of the people involved are from Brooklyn and have prior records.

There were about 900 people in the concert building at 17 Irving Place during the shooting.

Troy Ave, 30, whose real name is Roland Collins, was the first person shot. He was hit in the leg and is expected to recover. He was taken to the hospital.

A 33-year-old man was shot in the stomach and pronounced dead at Beth Israel Hospital. A 34-year-old man was shot in the chest and is stable at Bellevue Hospital.

A 26-year-old woman also was shot in the leg and was taken to Bellevue in stable condition.

No arrests were made and no one is in custody.

The shooting is not believed to be connected to TI, who left the green room before the shots were fired. But an appearance scheduled for later in the night at another club, 1 Oak, was canceled and police closed the club for a period.

Rappers Maino and Uncle Murda were performing when the shooting started. Officials said Thursday that the incident appears to be an ongoing dispute between two people that escalated. The NYPD is looking into whether the shooting was linked to a fight between crews associated with Maino and Troy Ave.

There were metal detectors for T.I. concert-goers at Irving Plaza.

Detectives know who was in the green room and will interview everyone there at the time of the shooting. They also will look at video footage from inside and outside the venue, and check nearby businesses for video.