HOUSTON, Oct.11 (Xinhua) -- At least two people were killed and 35 others injured following a chemical leak of hydrogen sulfide on Thursday at an oil refinery in Pemex Deer Park, about 18 miles east of Houston, Harris County Sheriff's Office confirmed on Friday.
At least one person was transported by helicopter to a hospital.
The incident sparked a shelter-in-place order for two East Texas cities, Deer Park and Pasadena,for about three hours.
The facility is a crude oil refinery owned by Mexico's national oil company Pemex. The company said in a statement that investigations were underway and that operations had been "proactively halted" at two units due to the incident.
The cause of the leak remained under investigation on Friday.
Hydrogen sulfide is a colorless gas with a strong odor. ■