A Texas sheriff says two workers at a Houston-area oil refinery were killed after hydrogen sulfide leaked at the plant

U.S. and Mexican investigators have begun probes of a fatal chemical leak at a Houston area oil refinery on Thursday owned by Mexico's state oil firm Pemex, officials said on Friday. Two contract workers were killed and up to 35 others treated for exposure to hydrogen sulfide gas during work on a unit at the 312,

The director of Mexico's state-owned oil company Pemex says two employees killed when hydrogen sulfide leaked at a Houston-area oil refinery were employees of a subcontractor performing maintenance work.