Story highlights Bomb threat closes the Ambassador Bridge between Detroit and Windsor, Ontario 
 
 A Coast Guard spokesman says it is "too soon" to determine who sent the threat 
 
 A similar threat last week closes the Detroit-Windsor Tunnel 
 
 A major bridge between Detroit, and Windsor, Ontario, reopened early Tuesday after a bomb threat shut it down for more than five hours, police said. 
 
 Authorities closed the Ambassador Bridge after a bomb threat was received around 7:15 p.m., according to Sgt. Eren Stephens, a Detroit police spokeswoman. 
 
 It finally opened at 1 a.m. after bomb-sniffing dogs "did not detect or find a bomb or suspicious device." 
 
 The U.S. Coast Guard stopped all maritime traffic below the bridge during the incident. 
 
 The Ambassador Bridge is the busiest commercial international crossing in North America with more than 10,000 commercial vehicles crossing the bridge on a typical weekday, according to the bridge's official website. 
 
 More than 25% of all commercial goods between Canada and the United States cross the Ambassador Bridge, the website said. 
 
 The closing followed last Thursday's closing of the Detroit-Windsor Tunnel, which also was prompted by a bomb threat. ||||| The Ambassador Bridge between Detroit and Windsor has re-opened, according to the U.S. Coast Guard. 
 
 
 
 Coast Guard Lt. Justin Westmiller said the bridge resumed commercial and recreational traffic at 1 a.m. Tuesday morning, hours after a bomb threat brought traffic on both sides of the bridge to a standstill. 
 
 
 
 Detroit Police Sgt. Eren Stephens said that bridge traffic should be cleared in time for the Tuesday morning commute. 
 
 
 
 The bomb threat shut down the bridge on Monday night, creating massive traffic backups for commuters and security headaches for authorities, the second time an international crossing between the cities has been threatened in the last week. 
 
 
 
 A man in Detroit called in the threat about 7:15 p.m., triggering the shutdown on both sides of the bridge, said Detroit Police Inspector Don Johnson Jr., who is in charge of homeland security. 
 
 
 
 “There is a bomb at the Ambassador Bridge scheduled to go off in 10 minutes,” was what the man said, Johnson said. 
 
 
 
 Detroit police were working with various federal and local agencies, including the Department of Homeland Security, the U.S. Coast Guard, the Bureau of Alcohol, Tobacco, Firearms and Explosives and U.S. Customs and Border Patrol. Specially trained K9s were brought in to scour for explosives, Johnson said. 
 
 
 
 It was unclear late Monday when the bridge would reopen. 
 
 
 
 “We take any threat very seriously and set in motion the security measures the bridge has had in place since 9/11,” said Dan Stamper, president of the Detroit International Bridge Co., which operates the Ambassador Bridge. 
 
 
 
 On Thursday, a bomb threat at the Detroit-Windsor Tunnel shut down that crossing and caused traffic backups for hours. Agents scoured the tunnel for signs of explosives with the same K9s. Commuters were forced to make detours to the bridge. That threat was determined to be a hoax. 
 
 
 
 Some traffic Monday night was being rerouted to the tunnel, but semi trucks were lined up for blocks, too big to use the tunnel. Many commercial trucks can’t clear the tunnel’s 13-foot, 2-inch ceiling. 
 
 
 
 Truck driver Matt Shellington, 43, had been waiting for two hours by 10:15 p.m., trying to return to Paris, Ontario, where he lives, after dropping a load of industrial hoses off in metro Detroit. He says he wasn’t too worried about the bomb threat or the wait. 
 
 
 
 “I don’t get too excited,” he said, but did point out that he still had three hours to drive once across the bridge.
– Is somebody in Detroit trying to keep Canadians out? The Ambassador Bridge linking Detroit with Windsor, Ontario, was shut down last night after a bomb threat was received from the Detroit side, reports CNN. The bridge is America's busiest commercial border crossing, with more than 10,000 commercial vehicles crossing on a typical day, and a huge amount of traffic quickly built up. The tunnel between Detroit and Windsor was closed due to a bomb threat last week and authorities say yesterday's threat was "similar." Detroit police, working with assorted federal and local agencies, scoured the bridge area for explosives while the Coast Guard stopped any maritime traffic beneath the bridge, reports the Detroit Free Press. "We take any threat very seriously and set in motion the security measures the bridge has had in place since 9/11," said the president of the Detroit International Bridge Co., which operates the bridge. Traffic was allowed to cross again after the bridge had been shut down for around six hours.