The U.S. Coast Guard said the search for a painter who fell from the Ambassador Bridge into the Detroit River will continue well into the night.
The U.S. Coast Guard got the call at 1:45 p.m. and deployed two boats and a helicopter to search for the man, who officials later identified as Kent Morton, 27, of Garden City, Mich.
The Detroit police dive team and a boat equipped with sonar joined the search for the fallen worker. The Michigan State police deployed a helicopter.
Construction equipment dangled from the bridge in the hours after the incident.
U.S. Coast Guard chief Gabriel Settel said witnesses saw the man fall into the water. The painter was last seen wearing work coveralls.
It is not known whether he was wearing a safety harness.
According to Randy Spader, the Ambassador Bridge's manager of operations, the man was working for a subcontractor of Seaway Painting of Livonia, Mich.
"First and foremost, our concern is for the man who fell this afternoon. We are praying for a positive outcome to this accident," Spader said. "I really don't know how this happened. We know the risk involved in this kind of work and our contractors abide by the highest safety standards."
Settel said the Detroit River's temperature was 2.7 C (37 F) at the time of the fall and that an average male can survive in the water of that temperature for up to seven hours.
Settel said the search was to continue into the evening hours and the coast guard will re-evaluate its efforts then.
It's not known how far the man fell, but at its apex, the 82-year-old bridge stands 46 metres (152 feet) above water.
The bridge remained open to traffic, which was moving smoothly just before rush hour.
Almost $500 million US in trade crosses the Ambassador Bridge on a daily basis. It is the busiest border crossing in North America with 28,814 trucks that cross the border daily in 2010.
Not first fall
A similar fall happened on Nov. 14, 2000, when Jamie Barker, a painter from Windsor, fell from the bridge into the river. His body was recovered from the river on April 6, 2001.
Barker was working for Manz Contracting Services at the time.
Manz owner, Dave Batten, told CBC News on Wednesday that his company does not have workers on the bridge at this time.
Two painters were rescued in June 2001 after scaffolding on the bridge between Windsor and Detroit collapsed, leaving them dangling 45 metres above the water below.
The men were painting a thick metal cable on the American side of the Ambassador Bridge when the scaffolding let go. Witnesses saw debris fall from the bridge and heard the men yelling for help.
After Barker's death, a coroner's inquest made 50 recommendations to improve the safety of people working on the bridge.