NEW YORK (CBSNewYork) – An MTA bus driver is in critical condition after trying to stop his bus from rolling into a cemetery in Queens early Tuesday.

The driver, identified by the Transport Workers Union as Kalib Olivier, got off the bus to take a bathroom break near All Faiths Cemetery in Ridgewood around 1:20 a.m.

The bus started rolling slowly backward down Metropolitan Avenue near 65th place and headed toward the cemetery’s gates.

Olivier first tried to reach through the driver’s-side window once the bus began go to roll. He then ran around to the passenger’s-side main door and tried to shove his way in. The bus rolled down the street and he was crushed between the door and a pole.

MTA officials said Olivier failed to properly secure the brakes, CBS2’s Erin Logan reported.

“We were going there with heavy hearts, thinking, ‘Not again,'” TWU representative Louis Marrero said.

Olivier suffered a punctured lung, broken arm and broken leg, according to the TWU. He taken to Elmhurst Hospital in critical condition but stable condition.

“He’s lucky, you know,” Marrero said. “He was just trying to do the right thing, and we — unfortunately, when we got to the hospital, he wasn’t conscious.”

The bus crashed into the cemetery’s fence. No one was on board it at the time.

Another driver, Anibal Rivera, saw the crash, secured the bus and contacted authorities, the TWU said.

“He may have saved [Olivier’s] life,” said J.P. Patafio of TWU Local 100. “Nobody else was around to see what had happened. I’m not an expert, but in my opinion, operator Rivera may have saved his life. He could have been dead.”

CBS2 is told Olivier has been an MTA bus driver for 12 years, and Rivera was not just a coworker, but the man who trained Olivier.

“He just kept telling him, you know, ‘stay with me, you’re OK, management is on the way, the ambulance is on the way,” Marrero said.

The MTA and NYPD are investigating how the bus wound up rolling backward in the first place.

In June, an MTA bus careened down the street in Brooklyn causing damage to 10 parked cars. The driver in that incident was suspended. It was her third day on the job.

In that incident, the driver apparently neglected to place the bus into park and left it in neutral.

She was out of work without pay for two months, according to the MTA. After rigorous re-training, she recently signed a new one-year probationary contract.

The MTA said bulletins and posters have since been issued on properly securing buses. Marrero added the union hopes to implement longer training programs.