US Coast Guard says debris field found near Titanic during search for submersible

The US Coast Guard says that an underwater vessel has located a debris field near the Titanic in the search for a missing submersible with five people aboard, a potential breakthrough in an increasingly urgent around-the-clock effort.

The Coast Guard’s post on Twitter gives no details, such as whether officials believe the debris is connected to the Titan, which was on an expedition to view the wreckage of the Titanic. The search passed the critical 96-hour mark today when breathable air could have run out.

The Titan was estimated to have about a four-day supply of breathable air when it launched Sunday morning in the North Atlantic — but experts have emphasized that was an imprecise approximation to begin with and could be extended if passengers have taken measures to conserve breathable air. And it’s not known if they survived since the sub’s disappearance.

Rescuers have rushed ships, planes and other equipment to the site of the disappearance. Today, the US Coast Guard says an undersea robot sent by a Canadian ship had reached the sea floor, while a French research institute says a deep-diving robot with cameras, lights and arms also joined the operation.

Authorities are hoping underwater sounds might help narrow their search, whose coverage area has been expanded to thousands of miles — twice the size of Connecticut and in waters 2 1/2 miles (4 kilometers) deep. Coast Guard officials said underwater noises were detected in the search area Tuesday and yesterday.