(Lexington, MN)  —  A college student is being mourned after she died in a house explosion.  Authorities say 20-year-old Kailey Mach was staying in a home on 211th Avenue in Lexington Township Saturday night to watch over the homeowner’s two dogs.  Officials say the explosion caused the house to catch fire and collapse.  The Augsburg University student’s body was found in the basement.  The cause of the explosion is under investigation.