Deer Park, Texas — At least two workers at a Houston-area oil refinery were killed Thursday when hydrogen sulfide leaked at the plant, prompting local residents to be urged to stay indoors before authorities later determined the public was not in danger.
Nearly three dozen other people were transported to hospitals or treated at the scene, Harris County Sheriff Ed Gonzalez said. Hours after the leak began, Gonzalez said the area was still unsafe for investigators to enter and officials may not be able to enter until Friday.
The plant is operated by Pemex, the Mexican state oil company, and is located in the suburb of Deer Park.
Gonzalez said the gas was released during work on a flange at the facility, which is part of a cluster of oil refineries and factories that make Houston the petrochemical heart of the country.
Pemex said in a statement that investigations were ongoing and that operations at two units had been “proactively halted” with the aim of mitigating the impact.
Local officials issued a shelter-in-place order but lifted it hours later after air monitoring showed there was no risk to the surrounding community, Deer Park Mayor Jerry Mouton said.
CBS Houston affiliate KHOU-TV chief meteorologist David Paul said winds were calm Thursday evening.
Hydrogen sulfide is a foul-smelling gas that can be toxic in high concentrations.
“Other than the odor, we have had no verifiable air monitoring showing that anything has moved outside the facility,” Mouton said.
Television news crews showed several ambulances and emergency vehicles at the scene. Gonzalez had originally posted on the social platform
The leak caused the second shelter-in-place order in Deer Park in a span of weeks. Last month is one pipeline fire that burned for four days forced to evacuate surrounding neighborhoods.