Investigators in Merrillville are requesting a structural engineer take a look at a pedestrian bridge that collapsed Saturday night, sending 50 people into a lake.

Police suspect a rusty I-beam is to blame for the collapse, and are looking for official records on the bridge's construction.

Ross Township trustees say the bridge was inspected about a year ago and was declared sound.

Police say the worst injuries sustained in the bridge collapse were a man who suffered a broken collarbone and woman who broke her leg.