Anadarko shares drop amid Colorado home explosion investigation

The Anadarko towers are shown Wednesday, Oct. 9, 2013, in Houston. The new Hackett Tower is shown on the left, and the Allison Tower is on the right. ( Brett Coomer / Houston Chronicle )

Investors lopped off $1.5 billion from Anadarko Petroleum Corp.’s stock-market value on Thursday on the news it’s cooperating with an investigation by Colorado officials into a fatal home explosion near one of its old wells.

Anadarko shares closed at $57.13 on Thursday, down 4.7 percent, or $2.83, from the previous day, its lowest price since last September. Anadarko’s market capitalization stood at $31.9 billion on Thursday.

State and fire officials haven’t concluded what caused the house blast that killed two men and injured a woman earlier this month in Firestone, Colorado. The home was recently built about 200 feet from an Anadarko well that another company drilled in 1993.

As a precautionary measure, Anadarko said it shut in 3,000 vertically drilled wells in northeast Colorado as it completes well-site inspections. Collectively, the wells produced about 13,000 barrels of oil equivalent a day.