Two people died when a mobile home exploded in Minnesota early Tuesday in a blast heard miles away.The explosion in Princeton prompted several calls to 911 shortly after 4 a.m., Mille Lacs County Sheriff's Deputy Aaron Evenson told the Minneapolis Star Tribune. The victims were Katherine A. Kreger, 61, and her husband, Royce E. Kreger Jr., 60.Property owner Stuart Bryan told the newspaper that he had been renting out the home to the couple. Bryan said he has owned the home for about 15 years and “never had a problem or an issue, and boom, it just blows up.”A dog also died in the explosion, the sheriff's office said, adding the blast could be heard 20 miles away.The cause is under investigation by the office of the Minnesota State Fire Marshal. He said deputies who went to the scene saw a tank shooting propane into the air.Princeton, a community of about 5,300 residents, is 50 miles north of Minneapolis.