The cause of a fire in a gin pole truck stolen Sunday night from Duke Drilling, 620 Hubbard St., continues to be under investigation, Great Bend Fire Chief Mike Napolitano said Thursday. A mobile home fire earlier that day at 5501 Ninth St. has been ruled accidental.A Kansas Fire Marshal’s Office representative and Great Bend Fire Department Capt. Luke McCormick investigated both fire scenes on Monday.The fire at Finer Mobile Home Park Lot 79 was reported at 1:27 p.m. Sunday. It was ruled an accident that involved the careless discarding of a cigarette.