Port Neches, Texas - An early morning explosion 27 Nov at a Port Neches facility of raw materials supplier TPC Group Inc. injured three people, the company said in a statement.
Houston-based TPC said two of its employees and a contractor were taken to hospitals after the 1am (0700 GMT) explosion in a processing unit at the butadiene plant.
"At this time, we cannot speak to the cause of the incident or the extent of the damage, but TPC is assembling a team to conduct a full and thorough investigation," the company said. "Emergency responders are still working to bring the event under control."
The company said teams have been dispatched to neighboring communities to conduct air monitoring.
CNN quoted local authorities saying the blast did extensive damage to the small city and that the fire was burning butadiene.
"There's extensive damage throughout the city," the Port Neches Police Department said, according to CNN.
The local fire department ordered an evacuation within a four-mile of the plant because of the potential for more explosions, CNN said. Port Neches is about 90 miles east of Houston.
In an update in the early morning of 28, CNN said a series of smaller explosions occurred throughout the day on 27 Nov, and a larger one in the afternoon "launched a tower into the air with balls of fire."
TPC has 426 kilotonnes per annum (ktpa) of butadiene extraction capacity at its Port Neches facility, with a further 417ktpa at its Houston plant, together representing 34% of US butadiene capacity, according to IHS Markit data.