The Green River Basin, where the Wyoming explosion at a natural gas field occurred. Creative Commons

A Wyoming gas field explosion injured five people Friday. According to The Associated Press, five of the six condensate tanks at the gas field owned by Alberta-based EnCana Corp. (NYSE:ECA) burst around 10:20 a.m. MST. Several people called the police to report the explosion.

The Jonah Field is located about 32 miles south of Pinedale in Sublette County in western Wyoming.

One of the five workers injured in the Wyoming explosion was in critical condition and was transported to a hospital in Salt Lake City. Another, who was listed as being in serious condition, was being treated at a hospital in Idaho. Two others were taken to hospitals and were in stable condition. The last was treated in Pinedale and released not long afterward.

Jonah Field, located in the Green River Basin, is a 21,000-acre natural gas field with that is being developed by several energy companies. The field is thought to sit atop roughly 10.5 trillion cubic feet of natural gas.

Firefighters and rescue crews were able to contain the fire caused by Wyoming explosion by 1 p.m., Reuters reported. So far, there has been no report of any harm to the environment.

What caused the Wyoming gas field explosion? Authorities are not sure yet, but an investigation is taking place over the weekend. The investigation is being led by the Occupational Safety and Health Administration, the federal agency responsible for enforcing health and safety regulations.

“We know that some welding work was being conducted on the condensate tanks on location, however the exact reason for the explosion is not known at this time,” Bridget Ford, a spokeswoman for EnCana Oil & Gas (USA) Inc., told Reuters. "Our thoughts are with our friends and co-workers that were hurt today, and their families.”

According to the Wyoming State Geological Survey, Wyoming is the third largest natural gas producer in the U.S. The average production for a Wyoming gas well in 2011 was roughly 208 thousand cubic feet per day. The state accounts for 10 percent of all U.S. natural gas production.