The top of the concrete guard rail, used to keep people from falling into the bay, showed a pattern of rust. Salt water had penetrated the top of the guard rail. The squares of rebar displayed a regular pattern of rust. The defective guard rail had a galvanized chain link piece of fence placed in front of it to protect the public.

A side view of the guard rail illustrated how the rust had followed a vertical piece of iron rebar. This allowed rust to travel down into the inside of the concrete guard rail. The internal rust had further weakened the concrete.