United States and Canadian ships and planes are racing against time to find a missing submarine two days after it disappeared off the coast of southeastern Canada while taking tourists to explore the wreckage of the Titanic.
The US Coast Guard said a boat on the surface - the Polar Prince - lost contact with the submarine, called the Titan, about one hour and 45 minutes after it began diving toward the site of the Titanic's wreckage on Sunday morning.
