One of the busiest bridges between the US and Canada has been reopened to traffic after a security threat shut it down for hours, just four days after a similar threat closed a nearby commuter tunnel that also connects the US city of Detroit to Windsor, Ontario.
Eren Stephens, Detroit police spokesperson, said early Tuesday that the bridge had been reopened at midnight after security sweeps failed to turn up any incendiary devices.
Detroit police said a call came in around 7:20pm to authorities on the US side of the Ambassador Bridge. The caller warned that a bomb would go off in 10 minutes along the busy freight crossing, police Inspector Don Johnson said during news conference Monday night.
The call prompted authorities in both cities to halt all truck and car traffic across the bridge.
Police had set up several roadblocks near the bridge, where canine units were called in to search the bridge. The Coast Guard was patrolling the Detroit River beneath the bridge and blocked river traffic.
The closing led to major traffic backups on expressways and other major roads leading into central Detroit, Stephens said. Car and light truck traffic was being diverted to the Detroit Windsor Tunnel about 3km away, though large trucks cannot use the underwater commuter tunnel.
A similar threat was phoned in Thursday to Windsor authorities that lead to a four-hour closing of the Detroit Windsor Tunnel, a busy border crossing beneath the river that also connects the two border cities. No explosives were found.
At the time, police said a man had called from a street pay phone and warned of a bomb on the Canadian side of the tunnel. Authorities have since said surveillance video from a coffee shop near the phone booth where the call was made might offer clues about the caller.
Stephens said Detroit police are leading the investigation into the bridge threat and working with state and federal law enforcement agencies.
Johnson said the call came in from somewhere in Detroit, though other details weren't immediately released.
Dan Stamper, president of the company that owns the bridge, told WJBK-TV that crews thoroughly inspected the bridge and had found no signs of explosives by Monday night.