An emergency medical technician died after a man riding on the bumper of her ambulance carjacked the vehicle and struck her with it Thursday night in the Bronx, NYPD said.

A passing motorist had alerted the two EMTs in the FDNY ambulance about the bumper rider, and when the EMT driver hopped out to investigate, the man jumped behind the wheel, authorities said.

As the EMT passenger fought the carjacker for control and the EMT driver tried to pull him out, the suspect put the ambulance in reverse and then in drive, NYPD Deputy Chief Jason Wilcox of the Bronx detectives said at Thursday night’s news conference at Jacobi Medical Center in the Bronx.

That’s when the EMT driver was knocked aside and struck by the tires of the ambulance as it turned from White Plains Road and crashed onto a snowbank and a car on Watson Avenue, authorities said.

“The car ran over her, and you could see it hop,” said music producer SwavyJayBeats, who was being driven home when he started videotaping the runaway ambulance.

The EMT victim was lying in the middle of the intersection when she lifted her head, seconds after the ambulance crashed, the music producer said.

“She was still alive because I saw her look at the person who did it,” SwavyJayBeats said. “My prayers go out to her and her family.”

advertisement | advertise on newsday

Witnesses held down the carjacker, 25, for police, authorities said. His name was not released.

Both EMTs were taken to Jacobi, where the victim, 44, was pronounced dead and her co-worker was treated for minor injuries and shock, authorities said.

City officials, including FDNY Commissioner Daniel Nigro, held back emotions at the hospital as they spoke to reporters about the victim, a mother of five and a 14-year FDNY veteran. Her name was not released, but Nigro said she was the eighth emergency medical services member to die in the line of duty.

“It’s a tough moment for all, but it’s a moment where we honor those who serve us and protect us,” Mayor Bill de Blasio said at the news conference.

He praised the bystanders who helped, naming MTA Police Officer Daniel McDade, who happened to see the tragedy unfold and subdued the suspect.

“A lot of heroism was on display today amidst the tragedy,” de Blasio said.

Nigro said the two EMTs had been on their way to a call when they were alerted to the bumper rider.

“They were acting very bravely,” Nigro said. “This person had no business being in the ambulance. It’s a sad night for everyone in the department.”