A motorcyclist died on the 91 Freeway in Long Beach after falling into traffic where he was hit by a semi-truck Tuesday night, according to the CHP.

Authorities said the 20-year-old man was riding eastbound in the No. 5 lane when he lost control and was thrown from the bike.

Investigators aren’t sure how fast he was going, but he landed in lanes and slid toward the back of a tanker-truck that was in a nearby lane, the CHP said.

The tanker’s trailer hit the man, leaving him lying in lanes until medics from the Compton Fire Department arrived, according to authorities. They determined the man was dead.

The coroner’s office identified him as Bryan Quintero, a Lynwood resident.

The CHP shut down the eastbound 91 Freeway for a few hours while they investigated the crash. They’re still trying to determine what caused the man to lose control.