By Liz Hampton

(Reuters) -Cleanup was ongoing on Wednesday morning after a chemical leak killed two workers and injured 30 others at a LyondellBasell Industries plant in La Porte, Texas, the company said.

The incident occurred on Tuesday evening at the facility’s acetyls unit, releasing roughly 100,000 pounds (45,000 kg) of a mixture that included acetic acid. An “all clear” was issued early Wednesday morning and air monitoring did not indicate actionable levels, Lyondell said in a statement.

The company said 24 of the 30 individuals taken to local hospitals have been released. The two individuals who died in the incident were contractors.

The incident marks one of the worst chemical disasters in the United States since a series of explosions at a TPC Group plant in Port Neches, Texas, in November, 2019. Although there were no fatalities and only three injuries, 60,000 people within a four-mile radius were told to evacuate the day before the U.S. Thanksgiving holiday.

An investigation into the cause of the leak was underway, and local and federal agencies, including the Occupational Safety and Health Administration, Chemical Safety Board, and Environmental Protection Agency, had all been notified, Lyondell said.

(Reporting by Liz Hampton in Denver and Erwin Seba in Houston editing by Jonathan Oatis, Diane Craft and Marguerita Choy)