A 400-foot deep sinkhole in Louisiana is getting bigger and today swallowed the boat of two cleanup workers who had to be rescued from the hole! The gaping hole is in Assumption Parish, La., about 50 miles south of Baton Rouge, and sits in the middle of a wooded area.According to ABC News.com, officials are still fearful of the possibility of explosions from nearby gas-filled caverns.

"It has expanded 50 feet and during that expansion there were workers that were working on the cleanup of the diesel," Kim Torres, spokeswoman for the Office of Emergency Preparedness, told ABCNews.com today.

The two workers were in a boat tied to a tree when the area where the tree grew fell into the sinkhole. They were rescued by airboat uninjured. The authorities called for a mandatory evacuation for residents of about 150 homes in the area.

Officials are not certain what caused the massive sinkhole, but hey think it might be becuase of a nearby salt cavern owned by the Texas Brine Company. The cavern was used for 30 years, but last year the cavern was plugged, and officials say that may have caused the sinkhole.

Louisiana's Department of Natural Resources required that Texas Brine drill a well to investigate the salt cavern as soon as possible. Texas Brine  obtained samples from the cavern and provided daily reports on the findings.

The sinkhole is on the outside edge of the salt dome where this particular brine well is located.