WASHINGTON — The police and fire departments in D.C. were still searching Friday for a construction worker who went missing in the Potomac River Monday.

Police said the worker went missing after a pontoon boat that was working on the Key Bridge overturned due to a strong current.

Two other construction workers were on board but were rescued.

A helicopter was used to search the area near the Key Bridge on Friday.

The cause of the accident is still under investigation.