Police say Mankato fire that killed two was no accident

Police and a state fire marshal's investigator say the natural gas explosion that touched off a fire that killed a North Mankato couple in their mobile home was not an accident.

The bodies of 31-year-old Shawn Marxen and 29-year-old Elizabeth Marxen were found inside the gutted mobile home at Camelot Mobile Home Park after the explosion and fire early Saturday. Their 12-year-old and six-year-old daughters were staying with a grandmother.

Investigators said natural gas was piped into the mobile home.

Deputy state fire marshall Casey Stotts says a a natural gas explosion occurred inside the trailer, and investigators found that the fire that accompanied the explosion was not accidental. He says the couple's injuries were caused by the explosion and fire and said there was no sign of an intruder.

Authorities wouldn't say how the explosion occurred. Police say they expect the investigation to take about two weeks.

--- Information from: Star Tribune, http://www.startribune.com