CROSBY, Texas (KTRK) -- Two workers were flown to Memorial Hermann Hospital after the explosion and remain in critical condition. A third worker never made it.
The explosion was felt as far away as Channelview and workers were all emotionally shaken.
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An employee said, "Over the loudspeaker, they said 'Everyone leave the unit, there's a leak.' After that, it was chaos and everybody started running." Another added, "We had to crawl under the gate because the gate was locked, and just run."
"After that incident in Houston a few weeks ago, it started bugging me. This is our profession, this is what we do," said a plant employee.
Working at these facilities can be incredibly dangerous.
"I said, 'Oh no, not again,'" said Dr. Ramanan Krishnamoorti, professor of chemical engineering and chief energy officer at University of Houston.
He says it's dangerous and difficult to be 100 percent safe at these plants and added, "Because of the fact it was a gas and it's held under pressure, you immediately have issues with explosions and potential loss of life associated with the explosions."
This isn't the first incident in recent weeks. The ITC tank fire in Deer Park last month involved a storage unit and gasoline, a liquid. The KMCO incident was a processing unit converting raw material, according to Dr. Krishnamoorti.
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The professor says it's a matter of concern along the Gulf Coast, with a growing number of chemicals being handled, shipped and stored.