A forest wildfire in Northern California was still blazing on Tuesday after trapping 85-100 Fourth of July celebrators in the area.

The Electra Fire, which started Monday at Vox Beach, a recreation area in Sierra Nevada Gold Country, tripled in size overnight to more than 4.7 square miles, the Associated Press reported. As of now, the reason for the blaze is not known, but firefighters believe it may have been caused by either fireworks or a barbeque from revelers celebrating the holiday.

The people celebrating were forced to find shelter at a Pacific Gas & Electric Co. Facility and were all reported safe as of Monday night, though they were unable to leave due to the danger of the fire. They were all eventually evacuated, Amador County Sheriff Gary Redman told AP News.

Approximately 500 people in Amador County and 300-400 people in Calaveras County have also been issued mandatory evacuation orders and warnings.

Other areas of the state were closed for the holiday to prevent these types of fires, like the North Etiwanda Preserve in Rancho Cucamonga.

In a statement Friday, the city said “to provide for public safety and prevent the ignition of a wildfire that can damage or destroy the natural resources of the region,” was the reason for the closure.