Anadarko Petroleum Corp., the state’s largest oil and gas producer, plans to shut down 3,000 vertical wells in northeastern Colorado after a fatal home explosion in Firestone near one of its wells. State regulators announced they are investigating the cause of the April 17 explosion that killed two men in a recently built home located within 170 feet of a well that was drilled in 1993 and later acquired by Anadarko. Frederick-Firestone Fire Protection District Chief Theodore Poszywak said his department also will continue to gather and analyze evidence to determine the cause of the explosion. “While the well in the vicinity is one aspect of the investigation, this is a complex investigation and the origin and cause of the fire have not been determined,” Poszywak said. He added that “there is no threat to surrounding homes” and said fire investigators have been in contact with surrounding residents. Anadarko said while a lot of unknowns remain about the explosion, it would shut in all vertical wells of that same vintage out of an “abundance of caution.” “Colorado residents must feel safe in their own homes, and I want to be clear that we are committed to understanding all that we can about this tragedy as we work with each investigating agency until causes can be determined,” Brad Holly, Anadarko’s senior vice president of U.S.