JULY 20, 9:15 P.M. UPDATE:

One lane on I-80 westbound has reopened following a crash involving multiple vehicles and a semi truck on Monday afternoon.

One lane remains closed, according to a post from Cal Trans District 3 on Facebook.

That lane is closed for hazmat work and vehicle recovery, according to the post.

ORIGINAL ARTICLE (JULY 20, 4:36 P.M.):

A westbound Interstate 80 closure in Placer County is affecting drivers after a collision involving multiple vehicles and a semi-truck.

According to Cal Trans District 3 in an online post, the closure is approximately 2.1 miles east of Baxter.

Drivers are encouraged to use an alternate route and avoid the area if possible. Officials said motorists should expect extended delays, and the estimated time to reopen the highway remains unknown.

Cal Trans District 3 said the closure is not related to construction.

It is unknown how many vehicles were involved, whether anyone was injured, or what caused the crash. This is a developing story, and updates will be provided as they become available.

(Cal Trans District 3 contributed to this story.)