NEW YORK (PIX11) — The Office of Chief Medical Examiner said Friday probationary firefighter Vincent Malveaux, 31, died from “complications of exertional rhabdomyolysis” last Dec. 3, a day after he collapsed at the FDNY training academy on Randall’s Island.

Rhabdomyolysis is a rare medical condition that starts with a breakdown of the body’s muscle tissue, which leads to a damaging protein being released into the blood. The protein can attack the organs, especially the kidneys.

The announcement about Malveaux’s cause of death came nearly six months after the young probie passed away.

FDNY unions had been concerned about multiple, on-duty deaths in the department since Malveaux died, some of them sudden, cardiac incidents.

The medical examiner’s office told PIX11 News Malveaux had a sickle cell trait, called Hemoglobinopathy, that was a contributing condition in his death.