Explosion injures over 30 people at Houston-area Exxon Mobil refinery

An explosion and fire at an Exxon Mobil oil refinery outside of Houston Wednesday left 37 people with minor burns, plant officials said.

Exxon Mobil Baytown Area said a unit processing propane and propylene burst into flames late Wednesday morning at the Olefins plant, forcing the city to issue a shelter-in-place order, according to Fox 26. Black smoke from the fire could be seen for miles. The explosion happened shortly after 11 a.m. and was contained by the afternoon.

"Our first priority remains the safety of people, including our employees, contractors and the community," Exxon Mobil Baytown Area said in a statement. "As a precaution, our industrial hygiene staff is conducting air quality monitoring at the site and at the fence line, and we are cooperating with regulatory agencies."

The company requested that some residents living west of the plant shelter in place as a precaution. At least two school districts in the area implemented shelter-in-place precautions for their summer activities, according to Fox 26.

Some workers have begun returning to the plant's entrance after evacuating and nonessential personnel were sent home for the day.

Plant manager Jason Duncan said Exxon Mobil had detected no adverse environmental effects in a press conference Wednesday afternoon. The plant is part of the company's 3,400-acre refinery complex in Baytown, located about 25 miles east of Houston.