House explosion kills husband, two sons of missing woman

(Reuters) - An "intentional" house explosion on Sunday near Tacoma, Washington killed the husband and two sons of a Utah woman missing since December 2009, fire department officials said.

The explosion happened shortly after a Child Protective Services worker dropped off the two children of Joshua Powell for a supervised visit, who then prevented the worker from entering the house, according to Graham Fire and Rescue Deputy Chief Gary Franz.

The worker reported smelling gas before the explosion, and was trying to report the incident to her supervisor when it happened, Franz said.

"Everything is telling us that this was intentional," Franz said. "This would be murder, if that was the case, on the part of Mr. Powell."

Powell's wife Susan went missing in December 2009, according to a website set up by her parents, friends and other family.

Susan and her husband Joshua both failed to show up to work on December 7, 2009, according to the site. Josh Powell returned later in the evening with their two sons and said he took them camping the night before, leaving Susan at home.

The police believe the disappearance was suspicious, the family said.

Firefighters were still working to contain the blaze and remove the bodies from the smouldering house, Franz added.

"This is an ugly situation right here," he said.

(Reporting By Mary Slosson; Editing by Greg McCune)