An energy facility burst into flames in Crockett, Contra Costa County, California on Tuesday afternoon causing widespread emergency responses. The incident took place at around 2.30 p.m local time (5.30 p.m. EDT) at NuStar Energy.

Local reports suggested that the fire had destroyed thousands of gallons of fuel at the Bay Area facility. It forced many people to stay indoors due to the presence of alleged dangerous particles in the air as a result of the fire. It was later determined that the facility’s two fuel containers had caught fire and they contained low amounts of ethanol and jet fuel.

The fire took the authorities almost seven hours to douse as the burning chemicals spewed long flames and massive black smoke into the air. Emergency services were alerted and a shelter-in-place was mandated in the surrounding area which was soon lifted after the officials determined the air particle levels to be safe for breathing. The nearby freeway was shut too around midnight but was later opened after the fire was doused.

The Contra Costa County Health Services tweeted, “Some neighborhoods near the NuStar facility have experienced higher-than-normal levels of particulate matter in the air, which is why the shelter-in-place order remains in effect in the area.” They also added a map of the area coming under the order.

The Bay Area Air Quality Management said the agency was sending an inspector to the site to investigate the air quality for any pollutants. The air quality was determined to be “good” before the fire erupted.

NuStar Energy is a publicly-traded master limited partnership based in San Antonio, Texas. The company issued a statement about the incident: “NuStar is working with first responders to extinguish a fire at its Selby Terminal in Crockett. There are two impacted tanks, which were holding very low volumes of ethanol – less 1% of tank capacity. All personnel are safe and accounted for. NuStar immediately enacted its emergency response procedures. Adjacent tanks are being cooled to minimize the risk of the fire spreading. We have contacted all regulatory agencies.”

The case was under investigation.