NEW YORK (CBSNewYork) -- Traffic was snarled for several hours on the Cross Bronx Expressway early Saturday after police say an 18-year-old driver was killed in a high-speed crash.

Investigators say his passenger is also in serious condition after the accident near the Bronx River Parkway exit in the Van Nest section.

The 18-year-old's sedan rear-ended a tractor trailer before hitting another car, according to police.

It happened just after 5 a.m. on the southbound side of the Cross Bronx.

The injured passenger was rushed to NYC Health/Hospitals + Jacobi.

No other injuries were reported as the accident remains under investigation.