U.S. and Canadian authorites weren't taking any chances Thursday: They temporarily closed an underwater tunnel linking the two nations after a bomb threat was phoned in to officials in Canada.
The Detroit-Windsor Tunnel -- the world's only underwater vehicular tunnel that runs through an international border -- was closed about 2 p.m. Thursday afternoon.
No bomb was detected, however, and the tunnel was expected to be reopened in both directions for evening rush hour, officials said.
"Nothing was found," Neal Belitsky, president and chief executive of Detroit-Windsor Tunnel, told the Detroit Free Press. Authorities said they thoroughly swept the tunnel and its environs with the help of a K-9 unit, and found nothing to suggest any danger.