The sinkhole sits on top of an underground mountain of salt and residents of Bayou Corne have been reporting tremors and gas bubbles for weeks. Despite a battery of diagnostic tests from federal, state and local officials, no one has been able to pinpoint the source of either occurrence.

When the sinkhole expanded Sunday, the owners of three natural gas pipelines at the edge of the liquefied area were asked to flare off and depressurize their pipelines as a precaution. Louisiana Highway 70 was temporarily closed and Gov. Bobby Jindal declared a state of emergency in Assumption Parish. At least 150 homes and several businesses were ordered to evacuate.

Four people in Assumption Parish have filed a federal lawsuit against Texas Brine, saying the sinkhole and resulting contamination caused damage to plaintiffs who are in need of medical monitoring. The lawsuit also says the public was never warned of any dangers that might be a result of drilling in the salt dome.

All four plaintiffs were forced to evacuate their homes as a result of the sinkhole. The lawsuit says the sinkhole and resulting contamination violated the Clean Water Act and the sinkhole was caused by "willful misconduct and/or willful negligence."