(CNN) Firefighters have made progress suppressing a Texas chemical plant blaze but authorities are keeping a mandatory evacuation order in place as a precaution.

Tens of thousands of residents within a 4-mile radius of the TPC Group plant in the small city of Port Neches evacuated their homes Wednesday after a series of explosions at the site, according to Jefferson County spokeswoman Allison Nathan. The chemical fire continued to burn on Thursday.

Jefferson County Judge Jeff Branick, who issued the mandatory evacuation, said Thursday firefighters were spraying water cannons over the blaze so the water vapors could cool the fire, causing it to burn out. The fire was contained but Branick said he wasn't prepared to lift the order until he felt it was safe for residents to return.

"I can confirm that the situation is improving, but we are not completely out of the woods as yet," Branick said.

Officials will meet at the plant early Friday to decide whether it's safe enough to lift the evacuation order, he said.

Read More