If you are in a high rise building and need to shelter in place, go to the first or second floor hallways or interior rooms. You want to stay on floors above floodwater or storm surge, but do not go to the highest floors due to wind impacts.
If you are under a tornado warning, seek shelter immediately in the center of a small interior room (closet, interior hallway) on the lowest level of a sturdy building. Put as many walls as possible between you and the outside.