An international search team detected underwater noises on June 21 as crews work to locate a tourist submersible craft that went missing Sunday in the North Atlantic.
A Canadian military surveillance aircraft detected the noises early Wednesday morning, the U.S. Coast Guard said in a statement, according to the Associated Press.
The Coast Guard did not specify what the noises could be, but it offered hope for finding the small submersible and its five passengers, as experts estimate as little as a day's worth of oxygen is left on the craft.
OceanGate's Titan craft disappeared on June 18 shortly after it dove to explore the wreckage of the Titanic, about 900 miles east of Cape Cod. The submersible is owned by OceanGate, a company that charters private tours to explore the famous shipwreck.
Businessman Shahzada Dawood and his son, Suleman Dawood, both British citizens, were among the five people were on board the 21-foot craft, NBC News confirmed.
Shahzada is the vice chairman of Engro Corporation Limited, which addressed the incident in a statement on Twitter.
“On Sunday, June 18, Mr Shahzada Dawood, Vice Chairman of Engro Corporation Limited, along with his son, Suleman, embarked on a journey to visit the remnants of the Titanic in the Atlantic Ocean,” the company’s statement read in part.
“All that we know so far is that contact I was lost with their submersible craft. There is limited information available beyond this that we know, and we humbly request that speculation and theorization is avoided.”
The Dawoods’ family also addressed the father and son’s disappearance in a statement obtained by NBC News.
“Our son Shahzada Dawood and his son, Suleman, had embarked on a journey to visit the remnants of the Titanic in the Atlantic Ocean. As of now, contact has been lost with their submersible craft and there is limited information available,” the family said.
“A rescue effort that is being jointly led by multiple government agencies and deep-sea companies is underway to re-establish contact with the submersible and bring them back safely,” the family’s statement continued.
“We are very grateful for the concern being shown by our colleagues and friends and would like to request everyone to pray for their safety while granting the family privacy at this time. The family is well looked after and are praying to Allah for the safe return of their family members.”
Billionaire Hamish Harding is also among the missing, his company, Action Aviation, confirmed to NBC News.
The Explorers Club, a group Harding founded, said in a statement on June 20 there is "cause for hope" in finding the submersible and its passengers.
"We understand that likely signs of life have been detected at the site," the club's president Richard Garriott said.
Harding has taken part in other high-profile adventure missions in the past. He flew to space in May 2022 as a passenger on the Blue Origin NS-21 mission.
In 2021, Harding also set a Guinness World Record for “the longest time spent traversing the deepest part of the ocean” during his dive to Challenger Deep in the Mariana Trench.
Stockton Rush, the CEO of OceanGate, is also on board the missing vessel, the company confirmed on June 20 in a statement. The French pilot of the Titan submersible, Paul Henry Nargeolet, is also on board the craft.
On June 19, OceanGate released a statement about the incident.
“Our entire focus is on the wellbeing of the crew and every step possible is being taken to bring the five crew members back safely,” the company said. “We are deeply grateful for the urgent and extensive assistance we are receiving.”
Search teams are now racing against time to locate the missing submersible, which has enough life support to sustain five crew members for 96 hours, or four days, according to OceanGate’s website.
The U.S. Coast Guard is working closely with Canadian search teams, conducting visual and radar aerial searches, as well as dropping sonar buoys in the water to listen for any signs of the missing sub.
“We’re hoping that they can pick up any unusual sounds, maybe tapping on the hull or voices or those types of things, any any signs of the vessel that are in the water,” Rear Adm. John Mauger, the commander of the Coast Guard district leading the search, told TODAY. “That’s why we’ve really pressed in with the capabilities that we have.”