At least two dead in chemical leak at facility near La Porte, Texas - CNN

Emergency responders from the City of La Porte and Channel Industries Mutual Aid are on scene," the LyondellBasell statement said.

"We are working closely with responders to confirm all employees are accounted for.

Air monitoring demonstrated no levels of concern for the community," the statement said.

In an earlier tweet, the emergency management office they said there was no impact expected on the surrounding community.

The first report came in at around 7:30 p.m., Woodward told CNN.

"LyondellBasell La Porte requested support from La Porte EMS regarding a mass casualty incident at their facility," he said.

The area is in unincorporated Harris County, adjacent to the City of La Porte, Woodward said.