An air ambulance carrying six people may have been "coming in blind" with electrical problems when a storm loomed ahead of it early Saturday shortly before it vanished in the waters off Nantucket.

The pilot reported electrical problems and declared an emergency as it approached the coast on the flight from Bermuda, according to air traffic control audio posted by LiveATC.net. "Roger, you said you're coming in blind. Is that what you said?" a controller can be heard asking the pilot.