The search for five people aboard the missing submersible that was exploring the Titanic wreck grew Wednesday to double the size of Connecticut and 2.5 miles deep, as noises picked up by sonar have yielded no leads and the vessel’s 96-hour oxygen supply is estimated to run out Thursday.

But the international search effort remains full of “hope and optimism,” said Capt. Jamie Frederick of the U.S. Coast Guard, adding that officials are still planning to recover a live crew.

“This is a search and rescue mission, one hundred percent,” Frederick said Wednesday afternoon. “We’re right in the middle of a search and rescue case, so I don’t want to get into a discussion about when that would end.”

Several Canadian P-3 aircraft detected underwater noises in the area where crews are looking for the Titan submersible, and operations were redirected there, the U.S. Coast Guard’s First District reported early Wednesday. Those efforts “have yielded negative results but continue,” the Coast Guard tweeted.... Read More: Washington Post