McALESTER, Oklahoma - A second wrongful death lawsuit has been filed over a natural gas rig explosion in Oklahoma that killed five men -- three from Oklahoma, one from Texas and one from Colorado.

The lawsuit by Betty Jo Cunningham, widow of Roger Cunningham of Seminole was filed Friday, a week after the widow of Parker Waldridge of Crescent filed a similar lawsuit. 

Each names Red Mountain Energy and Red Mountain Operating, both of Oklahoma City, and Patterson-UTI Drilling and Patterson-UTI Energy, both of Houston.

Patterson-UTI did not immediately respond to a request for comment, but previously said it's committed to preventing future such accidents. An attorney for Red Mountain did not immediately return a phone call for comment.

The January 22nd explosion also killed Matt Smith of McAlester, Josh Ray of Fort Worth, Texas, and Cody Risk of Wellington, Colorado.

The Associated Press contributed to this report.