GEISMAR, La. (AP) — Westlake Chemical Corp. crews were clearing chemicals Sunday from a tower damaged by an explosion and fire last week at the plant in Geismar, La.

A crane apparently arrived from out of state late Saturday, allowing crews to stabilize the tower that held an estimated 500 gallons of liquid ethylene dichloride, Peter Ricca of the state Department of Environmental Quality said Sunday.

"They must have been working through the night," said Ricca, DEQ's emergency response manager.

He said it had been leaning slightly since the accident Thursday, and had to be stabilized before anyone could go up to it to start getting out the remaining liquid.

"Once it's emptied out and any residual liquid cleaned out, it's not an environmental issue. It will be a mechanical integrity issue. I'm sure they'll be working very quickly to get it fixed," Ricca said.

Nobody was injured in the accident, which occurred as workers were restarting a vinyl chloride monomer unit. The vinyl chloride is used in making plastic pipe.

Ricca says air at the plant's boundary line was being checked hourly for safety.

Cause of the explosion and fire was still unknown, he said.

By this Thursday, he said, the company must give his department a report about what officials believe happened, and how much of what chemicals escaped. If some details aren't known, another report is due in 30 days.