The US Coast Guard is searching for a missing medical plane. Six people were on board.

The plane was flying from Bermuda to Boston. It was last reported off the Massachusetts coast.

The search is south of Nantucket. The Coast Guard sent aircraft, a helicopter and boats.

The search was set to continue overnight. Flight data showed a drop of at least 9,000 feet.

The drop took two minutes. Then the jet leveled off for several more minutes.

After that it disappeared. It lost contact with flight controllers after the big drop.

Reports say the pilot declared an emergency before contact was lost. A dispatcher also reported electrical issues and lost radio and radar contact.