At least four people are dead and many others are injured after two serious crashes in Nassau County.

The first happened Sunday just before 7:30 p.m. at Sunrise Highway and Unqua Road in East Massapequa.

Authorities say a vehicle traveling at a high speed crashed into at least three other vehicles. Vehicles could be seen flipped upside down near Sunrise Mall.

Mangled and destroyed cars littered the road, forcing police to shut down the highway. Firefighters used the jaws of life to remove people from the vehicles.

Three people were killed. Two people were rushed to the hospital in critical condition, two were sent in stable condition, and one was treated and released.

The second crash happened at 2:30 a.m. Monday in West Hempstead and at least one person was killed.

One car collided with a tree and an SUV crashed onto the road’s center median by Broad Street, authorities said.

An eyewitness recalled watching the SUV speeding east down Hempstead Turnpike, through a red light with no headlights on.

“He was speeding like 100+ miles at least. People saw him at Cherry Valley here speeding through the car. There was a whole family there, so it was very bad,” eyewitness Zein Mohamed said.

Officials say multiple people suffered life-threatening injuries.

Two victims were taken to Nassau County Medical Center. Officials say two others, who are believed to be children, were taken to Cohen Children’s Medical Center.

Investigations into the crashes are ongoing. Police have not revealed the identities of the drivers or any charges.