Concept cars burned after General Motors design facility in Pasadena catches fire

Multiple concept cars were burned and a hazardous materials crew was called to Pasadena after a General Motors design facility housing lithium-ion batteries caught fire on Wednesday night. 

Hundreds of firefighters were called to the scene after the four-alarm fire broke out at around 5:45 p.m. in the building located near Sierra Madre Villa Avenue and Rosemead Boulevard, according to the Pasadena Fire Department. 

The cause of the fire remained under investigation late Wednesday as crews continued to battle the fire, which was complicated by the presence of lithium-ion batteries inside the building. It's unclear if the batteries were being stored inside or if they were a part of the cars being developed by the company.

Firefighters said that it was difficult for crews to locate the fire inside the facility, where multiple concept cars being developed by GM were burned. 

They expect the cleanup to take days, and that hazmat teams would be on the scene to help secure the incident and provide safety for firefighters. Roads in the immediate area were closed for several hours as the firefight continued. 

SkyCal flew over the facility as firefighters continued their battle on Wednesday. Though no flames were visible from the exterior, there was a large layer of smoke over the building. Several fire engines were stationed around the property. 

The massive facility is a design center for mechanical engineers who work on General Motors' brand vehicles, which include Cadillac, Buick, GMC and Chevrolet.