A disgruntled former hospital worker armed with a rifle barged into the Bronx Lebanon Hospital Center Friday and opened fire, fatally shooting one doctor and wounding six other people before killing himself, New York City police officials said.

The suspect, identified by sources as 45-year-old Henry Bello, was found dead on the 17th floor of the facility, where he had tried to set himself on fire before he shot himself, according to NYPD Commissioner James O’Neill.

We’ve had a real tragedy here,” New York City Mayor Bill de Blasio said. “One doctor is dead and there are several more who are fighting for their lives right now.”

The mayor did not identify the slain doctor or those who were wounded. O’Neill said five of the wounded were in serious condition and the sixth had been shot in the lower leg.