Desperate air, sea search for small sub missing near Titanic

Rescue teams expanded their search underwater on Tuesday as they raced against time to find a deep-diving tourist submersible that went missing near the wreck of the Titanic with five people on board and limited oxygen.

All communication was lost with the 6.5-meter Titan craft during a descent Sunday to the Titanic, which sits at a depth of crushing pressure more than two miles below the surface of the North Atlantic.

The submersible was carrying three fee-paying passengers -- a British billionaire, and a Pakistani tycoon and his son. The US and Canadian Coast Guards have deployed ships and planes in an intensive search for the vessel, which is equipped with just four days of oxygen. France's oceanographic institute said it was sending a deep-sea underwater robot to aid efforts.