An out-of-control driver “kept hitting the gas” as he plowed down a Harlem street, killing a bicyclist and injuring four other people on Thursday night, according to authorities and witnesses.

A 49-year-old man driving a Red Hyundai Tucson ran over two bicyclists, aged 33 and 28, and barreled into a parked NYPD cruiser near West 125th Street and Frederick Douglass Boulevard at around 8:05 p.m., police said.

The driver also collided with multiple other vehicles, including a tractor-trailer truck, according to witnesses and cops. 

The injured cyclists were both brought to local area hospitals in critical condition, while the Hyundai driver was not injured in the crash, cops added.

The 28-year-old cyclist was later pronounced dead while the other remains in critical condition, according to authorities. 

Three others were injured in vehicles that were stuck. A 40-year-old man in a Rav4, as well as a 23-year-old man and a 28-year-old man inside a Lexus, were all taken to local hospitals in stable condition.

One witness, Jonathan Morillo, told The Post he saw the driver plow into a gray car and into a truck — sending debris flying into the side of his vehicle.

“It was like an explosion, the gray car was waiting over here, then the pieces. They flew off, hit my car too, and then ran into the truck over there,” Morillo recalled.

“I was panicked. I was in shock. It’s like I saw everything in slow motion … everything happened so fast,” Morillo said.

“A lot of pieces all over the place … and then the guy just kept hitting on the gas. Like he was trying to escape.”

An unidentified person of interest was detained at the scene. Charges are pending, according to authorities.

The incident remains under investigation.