RIVIERA BEACH, Fla. » Five people, including three teenagers, were killed today in Florida after their car was hit by another vehicle that jolted through an interstate exit ramp, authorities said.

The driver of a 2008 Mercedes is believed to have been speeding as he exited Interstate 95 and ran a red light in Riviera Beach, about five miles north of West Palm Beach, shortly after midnight, Florida Highway Patrol Lt. Tim Frith said.

Twenty-one-year-old Jabari Kemp’s vehicle slammed into a 1994 Lexus carrying five people, the youngest 14 and the oldest 22. The impact ejected four people from the car. Only one passenger was wearing a seatbelt, Frith said.

Four of the people in the Lexus were pronounced dead at the scene. A fifth died after being taken to a nearby hospital.

“It’s every parent’s worst fear,” Frith said. “The families right now are the main concern.”

Killed in the crash were: Makita Campbell, 14; Shonteria Grimsley, 17; Jason Mahlung, 21; and Christina Oliver Joseph, 17, all of Riviera Beach, in South Florida. A 22-year-old man also killed in the crash has not yet been identified.

Kemp was taken to St. Mary’s Hospital in serious but not life-threatening condition. Frith said troopers will conduct a complete traffic homicide investigation. No charges have been filed. Frith said Kemp’s blood also will be checked for any indication of drugs or alcohol.

“We’re not ruling out anything at this point,” Frith said.

The two young men in the Lexus had been at an apartment complex until around 11:30 p.m. Friday, Frith said. Sometime thereafter investigators believe they picked up the three girls who were seated in the back of the vehicle, Frith said. He said troopers don’t know where they were headed.

Frith said Kemp was traveling at “a high rate of speed” as he exited the ramp and hit the Lexus. Debris from the crash struck a third vehicle, but the driver was not injured.

There was no answer today at a telephone number listed for Kemp’s family in Florida.