Aug. 17 (UPI) -- Colorado authorities said Thursday they have found the bodies of a mother and two daughters who disappeared earlier this week.
Shanann Watts and daughters Bella, 4, and Celeste, 3, disappeared Monday. Chris Watts, the woman's mother and the girls' father, has been charged in their deaths. Authorities believe the three were killed inside their home in Frederick, Colo.
A body found at Anadarko Petroleum Co., where Chris Watts had worked, is believed to be Shanann Watts.
The girls' bodies were found inside oil and gas tanks that "were mostly full," KMGH-TV reported.
"This is absolutely the worst possible outcome that anyone could imagine," John Camper, director of the Colorado Bureau of Investigation, said at a news conference.
Anadarko said Thursday it had fired Watts.
"We are heart-broken by this, and our thoughts and prayers are with the loved ones and friends of the Watts family. We will continue to support law enforcement in its investigation," company spokeswoman Jennifer Brice said in a statement.
Police arrested Watts Wednesday after he purportedly confessed to killing all three. He was booked Thursday and charged with three counts of first-degree murder and three counts of evidence tampering.
The three were reported missing Monday after a family friend hadn't heard from Shanann. Chris Watts initially said she'd disappeared, leaving behind only her purse and keys. The woman had just returned to Frederick hours earlier from a work trip to Arizona.