Authorities continued searching Sunday off the Massachusetts coast for a medical aircraft carrying six people that disappeared while flying from Bermuda to Boston. The U.S. Coast Guard said crews were preparing to deploy sonar equipment to examine the ocean floor for possible wreckage.

The Federal Aviation Administration alerted the Coast Guard around 2 a.m. Saturday after losing contact with the Gulfstream G100 over the Atlantic Ocean. The Canadian-registered aircraft was carrying four Canadians and two Bermudian nationals. Later Saturday, search teams discovered a “debris field” near Nantucket, Coast Guard Northeast District Rear Adm. Matt Lake said during a news conference Sunday.

The Coast Guard, New York National Guard’s Air Rescue Wing and Massachusetts authorities have covered approximately 2,840 square miles (7,356 square kilometers) using aircraft, helicopters, boats and cutters.

“This is a large and demanding search area,” Lake said.

The debris field lies in waters approximately 80 to 90 feet deep (24 to 27 meters). Lake said sonar equipment was being prepared to help crews search the seabed.

Authorities have also been keeping the families of those aboard the aircraft informed about developments, Lake said. Coast Guard Capt. John McTamney, the Northeast District’s chief of response, added that weather conditions have not disrupted the operation.

“We’ll continue to search and saturate the area until we’re at the point where we are confident that if there were any survivors remaining on the surface of the water, we would have found them,” McTamney said.

According to a statement from Bermuda airport operator Skyport, the aircraft departed L.F. Wade International Airport on a nighttime flight to Massachusetts with four crew members and two passengers aboard.

Air traffic control recordings suggest the aircraft may have encountered serious problems as it approached the coast, with a storm looming ahead shortly before it disappeared.

The pilot reportedly experienced electrical problems and declared an emergency, according to audio posted by LiveATC.net. During the exchange, an air traffic controller can be heard asking: “Roger, you said you’re coming in blind. Is that what you said?”

Mary Schiavo, a former Inspector General of the U.S. Department of Transportation, believes the aircraft may have lost its navigation instruments as a storm moved across its path. Preliminary data from flight-tracking service FlightRadar24 also shows the jet descending rapidly from approximately 24,000 feet to around 10,000 feet.

“Something bad happened with this big drop, and they flew into this big storm. It’s a terrible place to have a loss of your instruments and be flying blind,” said Schiavo, who is an aviation attorney. “It’s very easy to get disoriented and not know if you’re turning, climbing, descending, etc.”

Canada’s Transport Minister Steven MacKinnon said his department was monitoring the incident and coordinating with authorities involved in search-and-rescue efforts. He shared the update on X.