Florida Highway Patrol is investigating a deadly crash on I-95.

It happened early Sunday morning in the northbound lanes of the interstate, near Southwest 10th Street in Deerfield Beach.

According to authorities, a single driver began to slow down for traffic when a driver traveling behind him with a car full of people slammed into the back of the first car.

A total of five people were in that second car, and troopers said the person sitting in the left rear passenger seat was not wearing a seatbelt. That person sustained fatal injuries as a result of the crash.

Local 10′s cameras arrived at the scene just as tow trucks were taking away the two cars involved in the crash.

The crash is still under investigation.