Investigators are trying to determine what caused a fire in a plastic receptacle for house-keeping towels in an Aberdeen hotel Tuesday morning. The fire was discovered just before 11 a.m. by a security guard at the Hilton Garden Inn in the 1000 block of Beards Hill Road, according to a notice of investigation from the state fire marshal's office. Six firefighters had the fire out in about a minute. The hotel had working smoke alarms, which did not activate because the fire didn't generate enough smoke or heat, investigators said. Damage is estimated at $50. Anyone with information about the fire is asked to call the Office of the State Fire Marshal, 410-836-4844.