A chemical leak late Thursday evening caused the closure of a major freeway in California, forcing officials to evacuate about 170 residences from within a half-mile radius of the leak.
John Crater, the chief of the Riverside County Fire Department, said at a press conference on Friday that all homes and businesses were evacuated.
The leak occurred in the southern part of the state, near San Bernardino, and forced part of Interstate 215 to shut down on Friday.
The department said in a tweet that a substance leaked from a rail car. The department’s website said its hazardous materials team and Riverside County environmental health officials were working to mitigate the leak.
Crater said the material — identified as styrene, a chemical used in rubber and plastics products — is supposed to be stored at 85 degrees Fahrenheit but was at more than 300 degrees. He said the initial plume coming out of the rail car spread in the wind.
Officials said they were isolating the area and monitoring the temperature but did not immediately know how the leak started.
A center has been opened at a nearby middle school for evacuees, according to the fire department’s website.
Crater said he spoke to experts from various states who told him the issue should resolve itself within a couple days, but warned that if heat and pressure build in the car it could cause some type of explosion.
“That’s why we’re taking an abundance of caution with this,” he said. “We’re still in a pretty critical situation.”