California's Delta Fire in Shasta County tripled in size overnight, forcing the closure of Interstate 5 in both directions as flames engulfed vehicles and drivers abandoned at least 17 tractor-trailers. 

The fire broke out around 1 p.m. on Wednesday afternoon and has burned more than 38 square miles with zero percent containment. No injuries have been reported, but evacuations were issued on both sides of I-5 north of Lakehead to the Shasta-Siskiyou county line. About 300 people have evacuated from the area. Trinity County residents of East Fork Road to Ramshorn Road were also told to evacuate Thursday afternoon.

(MORE: The Latest on California's Delta Fire)

Local reports confirmed several homes were destroyed by the blaze, and nearly 300 remain threatened.

Hundreds of firefighters responded to the blaze, which officials have reported was human-caused, but it's not yet known if the fire was set on purpose.