The U.S. Chemical Safety Board announced it has opened an investigation into the chemical tank implosion that happened at a paper mill in Longview, Washington. In a news release, the agency said it has sent a team to the area that is on the ground as of Wednesday.

Officials have lifted all evacuation orders related to an overheating chemical tank in southern California, a day after a crack in the structure eliminated the risk of a catastrophic blast.

Nine others are unaccounted for, with officials not expecting to find survivors. An unknown amount of the corrosive substance spilled into the Columbia River.

Authorities are bracing for the possibility that a damaged chemical tank at a facility in Southern California could leak or explode.

The evacuation order has been lifted for residents in Garden Grove after authorities determined that the threat of a catastrophic toxic chemical tank explosion had been eliminated.

Experts say implosions of this kind are extremely rare – and do not happen by themselves. The KING 5 Investigators looked into what went wrong.

Firefighters on Saturday were trying to cool a chemical tank “literally on the edge” of exploding in Garden Grove, California, as they worked to avert a disastrous “worst-case” scenario, the incident’s commander said.

I’m kind of shocked that an insurance company would almost root for something to happen in order for you to be made whole,” a victim said.