Superdome specs say it can withstand 200 mph winds. Of course, what the specs say and what could happen in the real world may be totally different.
And the Titanic was unsinkable
The round shape offers good areodynamics in winds may come from any direction. Near Pensacola, a 'dome house' made of reinforced concrete and on the beach survived Ivan head-on last year. All the homes around it were gone! NBC had a camera crew there and they filmed the storm surge coming in.