You don't visit a neighbor or shop at an Allegheny County store anticipating you'll be hurt. You assume others will maintain a safe property the way you do. This safety agreement is more than common courtesy -- the property owner is obligated to take reasonable steps to protect visitors from injuries.
A woman preparing to take a flight out of Philadelphia International Airport suffered serious injuries in a departure lounge. The out-of-state resident recently filed a premises liability claim stating a chair in the waiting area collapsed, when the woman sat on it. The passenger's head and back hit a wall when she fell backward.