(CNN) For the second time in three weeks, a Houston-area chemical plant caught fire, sending thick plumes of black smoke into the sky.

At least one person was killed Tuesday at the KMCO plant in Crosby, Texas, Harris County Sheriff Ed Gonzalez said. Two others were in critical condition and were taken by helicopter to a hospital, fire marshal's office spokeswoman Rachel Moreno said.

The fire was put out late in the afternoon, the fire marshal's office said, though firefighters were still having to deal with hot spots.

The incident likely started when a transfer line ignited in the area of a tank holding isobutylene , according to the sheriff. An adjacent storage building also caught fire.

All residents within a 1-mile radius of the plant were ordered to shelter in place, the Harris County Sheriff's Office said, but that lockdown was lifted hours later. There does not appear to be hazardous chemicals in the air.

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