Hurricane Katrina ripped away part of the roof on the Louisiana Superdome as thousands of storm refugees huddled inside Monday. Strips of metal were peeled away, creating two holes that were visible from the floor of the huge arena. Water dripped in and people were moved away from about five sections of seats directly below. Others watched as sheets of metal flapped visibly and noisily. From the floor, more than 19 stories below the dome, the openings appeared to be 6 feet long. "The superdome is not in any dangerous situation," Gov. Kathleen Blanco said.