A violent crash involving five cars in Park Slope left several people hurt. Now police are investigating whether or not the crash was the result of a drag race pile-up.

A witness tells News 12 that she heard drivers racing up and down the street, so many times that she actually started recording on her phone.

The witness’s cellphone video shows cars flying down Fifth Avenue and swerving around other cars on the wrong side of the road.

Just moments after she stopped recording, she said she heard the crash.

"They were absolutely 100% racing,” says the witness.

Police tell News 12 that a livery cab driver in an Infiniti SUV was headed southbound on Fifth Avenue and trying to make a left onto Fifth Street when the driver of a G35 Infiniti, a 30-year-old woman, tried to go around him on the left and ended up crashing right into him, spinning out of control and hitting an unoccupied parked car.

Police say at the same time a 26-year-old man who was behind the wheel of a Ford Mustang and had also moved over into oncoming traffic, tried to avoid the crash, spun out of control and hit a parked Toyota Camry that had a 66-year-old woman and a 74-year-old man inside.

"They could've easily killed someone,” says the witness.

Police say the Uber driver had two passengers, a man and a woman. Both were taken to the hospital, as well as two others who were in one of the parked vehicles. They are all expected to make a full recovery.

So far no charges have been filed.