At least four oil workers were injured after an explosion at a refinery near Los Angeles on Wednesday.
The injured workers were contractors with Exxon Mobil, Reuters reports.
The explosion was so powerful that some residents thought there was an earthquake, KTLA reports. The incident comes amid a strike by United Steelworkers union members over health and safety issues.
The refinery, located in Torrance, California, is not involved in the strike.
Structure appears damaged after "explosion" at ExxonMobil Torrance Refinery http://t.co/DSSQXX80KFpic.twitter.com/fT3InYWkr8
— KTLA (@KTLA) February 18, 2015
USW was scheduled to meet with Shell, the oil company leading the negotiations, on Wednesday.
Lynne Hancock, a spokeswoman for United Steelworkers, said members were concerned about fatigue, “unsafe” staffing levels and the replacement of outgoing union workers with contractors.
“We have some workers who end up working 12 hour days for weeks on end.” Hancock said. “When people work this excessive overtime, they get fatigued. And when they get fatigued they can make an error that can be truly catastrophic.”
The 5,000-member strike at 11 sites is the largest held by U.S. refinery workers in more than 30 years.
Attempts to reach Royal Dutch Shell were not successful at the time of this writing.
Gavin Stern is a national digital producer for the Scripps National Desk.
