An explosion early Wednesday at the TPC Group plant near Beaumont, Texas, prompted evacuations and an order that all 16,000 people in one town stay indoors.
Three injuries have been reported, all of them staff at the Port Neches refinery site in East Texas, company officials said.
The Nederland Volunteer Fire Department called for "a mandatory evacuation for everyone within a half-mile of the TPC plant" about an hour after the explosion, which happened about 1 a.m.
"This could change and expand to a greater area," the department posted.
In Groves, Texas, south of the plant, the fire department warned the entire town to "shelter in place." The order was lifted about 6:30 a.m.
"Due to a wind shift the smoke plume has shifted in our direction. The plume is coming from unprocessed crude oil," the town's fire department posted on Facebook.
"The event is ongoing, but will be brought under control as quickly and safely as possible," TPC officials said in a statement early Wednesday.
"Right now our focus is on protecting the safety of responders and the public, and minimizing any impact to the environment."
The plant has been evacuated, and all staff have been accounted for, officials said.
Alica Wolfford Almaraz, who says she lives in Groves, posted photos on Facebook of the fire and reported "select neighborhoods" were being evacuated.
"There was a LOUD boom and huge fire," she wrote. "Lots of reports of blown out windows and house damages ... .lots of freaked out people. Please keep all emergency workers and plant workers in your prayers as they deal with the aftermath."
The plant is 300 miles southeast of Fort Worth, Texas, near the Louisiana border.
