You can't really worry that much about it. Bad things just happen. Worry more about slipping in your shower or getting into an accident in the parking lot.
The worst story like this I remember when living in NYC involved the metal protective railings along the curbs in Soho and Chinatown. There was some crazy utilities issue underground and the railings became electrified. Some poor young woman just happened to be stepping on the curb at that moment and was electrocuted to death. That shit made me scared of metal curbs for weeks. You can't walk around being scared of curbs.