SACRAMENTO COUNTY (CBS13) – A deadly crash has one lane blocked on southbound Interstate 5 south of Elk Grove on Thursday.

The crash happened a little after 10:30 a.m. near Twin Cities Road.

A big rig went off the side of the freeway and crashed into a tree. Exactly what caused the big rig to crash is unclear.

California Highway Patrol confirms at least one person has died in the crash.

The number 2 lane of southbound I-5 is closed. Traffic is backing up to Hood-Franklin Road, Caltrans says.

Authorities are asking drivers to consider taking alternate routes.