CROSBY, Texas (KTRK) -- Firefighters battled a chemical plant fire at KMCO at 16503 Ramsey Road, just off the Crosby Freeway in east Harris County for more than five hours on Tuesday.
WATCH: Powerful explosion caught on doorbell cam in Crosby
One person has died at the scene, according to the Harris County Sheriff's Office. Two people were taken to area hospitals by Life Flight. Their conditions have not been released.
Late Tuesday evening, the Harris County Fire Marshal's Office announced it has issued a subpoena for Diversified Shelters LLC., as part of its investigation into the cause of the KMCO fire.
The Texas Attorney General's Office has also filed a petition against KMCO for violations of the Texas Clean Air Act after the fire sent a black column of smoke into the skies over Crosby.
The executive director of the Texas Commission on Environmental Quality said the petition seeks a permanent injunction, civil penalties and costs related to investigating the blast.
"I offer my condolences to the families who have suffered injury or loss and to the community impacted by the KMCO fire earlier today," says TCEQ Executive Director Toby Baker.
Early Tuesday, a shelter-in-place was ordered for all residents within a 1-mile radius of the KMCO plant fire. That order was lifted by mid-afternoon.
A number of school districts had sheltered students in place following the blast. Those precautions have been lifted and the students have been released.
One worker told ABC13 a leak was detected just before the blast. He said workers were scrambling out of the area, even crawling under fencing to get away.
"They told us there was a leak first," said plant worker Randy Villalobos. "So we were leaving. In the process of leaving. The plant blew up. What were you thinking? I'm sure you heard it, you felt it. Just to get out. Get out as fast as you can."
"They told us there was a leak and get out," said Francisco Castillo, who was working at the KMCO plant manufacturing steel pipe. "It exploded before you got out. It really exploded when we were getting out.
Harris County Sheriff Ed Gonzalez says the preliminary information is that a transfer line ignited in the area of a tank with Isobutylene and the tank caught on fire. An adjacent storage building with solid goods also caught fire. Firefighters are currently working to contain it.
"It was very frightening," said plant worker Justin Trahan. "I've got to say I've only worked in plants for a few years. After that incident in Houston a few weeks ago, it actually started bugging me because this is our profession. This is what we do. But it's just always something that happens elsewhere. "
TCEQ emergency response personnel are monitoring the air quality in the vicinity of the fire.
The company issued the following statement from John C. Foley, President and CEO of KMCO: "There was an incident resulting in an ignition and fire today at KMCO, LLC in Crosby, Texas. We are deeply saddened to confirm at this time that there have been injuries and one fatality. Those injured have been transported for medical treatment. Our hearts and prayers go out to the individuals involved, as well as our first responders, employees and our community. We have activated the company's emergency response team and incident command center. We are working with local first responders to extinguish the fire. We will give another update as additional information becomes available. We apologize for any inconvenience to residents in the vicinity. The wellbeing of our people, neighbors and the environment remain our top priorities."
Residents report their homes shaking and seeing a thick column of smoke rising into the air. Some residents are evacuating as a precaution.
KMCO released a statement around 9:30 p.m. Tuesday in response to questions from the media and community:
"KMCO, LLC acquired the Crosby facility in 2012. Therefore, KMCO, LLC did not own or operate the Crosby facility and is not responsible for any historic incidents or violations that occurred prior to 2012. After the acquisition, KMCO, LLC's new owners and new management team dramatically accelerated the process of transforming the company by investing tens of millions in new capital and re-investing ongoing profits in people, processes, policies, and facility upgrades to safeguard our employees and the community, as well as the integrity and sustainability of our business. We will work with authorities to investigate today's incident thoroughly to prevent it from ever happening again. And with the help of our dedicated team, we will continue our mission of transforming KMCO into a next-generation, best-practice operator that meets and even exceeds the expectations of our customers, employees, surrounding communities, regulators and the industry at large."