Wilson, who was reportedly a fitness trainer, returned to the gym around 1 p.m. and shot his former colleagues, General Manager Janine Ackerman, 35, and Marios Hortis, 42, before killing himself.
One man, who was reportedly in the men’s locker room at the time of the shooting, said that he heard five gunshots, according to ABC News.
"It was too loud for it to have been a weight dropping. Within two seconds, people just started running out," Ovi Viera told the station.
Another witness, who was also inside of the gym, said he knew Wilson.
"He's not a crazy guy," the man told the Herald. "This wasn't someone who decided to kill a bunch of people. There was a dance class of 40 people if he wanted to do that. This was personal."
An Equinox spokesperson said Ackerman was a “kind and caring soul” and that she was loved and will be deeply missed. The spokesperson added that Hortis' spirit will be remembered.
"His generous spirit and warm demeanor made him an always welcome presence in our world," the gym said in a statement.
Both Ackerman and Hortis were taken to a nearby hospital in critical condition after the shooting, but died during treatment, according to reports.