A medical transport jet carrying six people vanished over the Atlantic Ocean early Saturday after declaring an in-flight emergency, prompting an overnight search by the U.S. Coast Guard off the coast of Nantucket, Massachusetts.

The Canadian-registered Gulfstream G100, operated by Hamilton, Ontario-based Latitude Air Ambulance, departed L.F. Wade International Airport in Bermuda at 11:41 p.m. Friday bound for Boston Logan International Airport. On board were two pilots, two medical personnel, a patient and a family member — four Canadian citizens and two Bermudians, according to Boston.com.

Flight-tracking data reviewed by the Boston Globe shows the aircraft cruising normally at 24,000 feet for most of the roughly 800-mile route before it began descending while still about 128 miles south of Logan Airport. Around 12:46 a.m., the crew declared an emergency reporting electrical and radio problems; the plane then lost radar contact, radio contact and its anti-collision transponder signal. The Federal Aviation Administration issued a search-and-rescue alert at 1:20 a.m.

Multi-agency search

The Coast Guard scrambled an extensive array of assets, including an HC-144 Ocean Sentry and an HC-130 Hercules fixed-wing aircraft, an MH-60 Jayhawk helicopter, a 47-foot motor lifeboat out of Station Brant Point on Nantucket, and the fast-response cutter William Sparling. Search crews focused on waters south of Nantucket, where the jet's signal was last recorded.

"Our thoughts are with those on board and their loved ones as the search continues," said Massachusetts Port Authority spokesperson Jennifer Mehigan.

Massachusetts Governor Maura Healey said the state would "do whatever we can... to support efforts there and work with the Coast Guard." Canada's transport minister, Steven MacKinnon, confirmed Canadian nationals were aboard but did not release names, citing the ongoing search and respect for families.

As of Saturday morning, no debris or survivors had been located, and officials had not speculated on a cause. Investigators are expected to examine whether the reported electrical failure is linked to the jet's descent and loss of contact once search operations conclude.

Latitude Air Ambulance, which has operated medical transport flights out of Hamilton since 2009, has not issued a detailed public statement beyond confirming the flight was its aircraft. The route between Bermuda and Boston is a common corridor for medical evacuations from the island, which lacks advanced trauma and specialist care for complex cases.