A blast at an ExxonMobil refinery in Los Angeles county Wednesday left four people injured and shattered the windows of nearby buildings.
The explosion ripped through the 155,000 barrel per day refinery just before 9:00 a.m. Wednesday in Torrance, sending ash raining down on nearby homes.
Inspectors said a small filtration device in a processing facility at the plant may have caused the blast.
The unit were the explosion occurred has been shut down but the rest of the refinery is still operating.
Emergency officials have found no evidence of foul play, Reuters said.
Fire crews extinguished a small ground fire caused by the blast and contained a gas leak at the plant.
Four contractors were taken to a local hospital for minor injuries.
ExxonMobil said all of the refinery’s personnel have been accounted for.
“Emergency procedures have been activated to address the incident, and employees are working with the appropriate agencies,” ExxonMobil said.
The refinery was visibly damaged by the blast and officials said the smell of gas continues to linger around the accident site.
A smoke advisory was issued for the area around the refinery and residents have been advised to stay indoors.
“You could feel it. It was like a loud sonic boom. My first reaction was, this doesn’t sound good, this doesn’t look good. Let’s get out of here,” refinery worker told NBC 4.
Officials from Caltech said the blast was equivalent to a 1.7 magnitude earthquake.