At about 04:55 Atlantic time, a Cessna 402C on a Part 135 mail flight apparently crashed into the Caribbean Sea near Vieques. The wreckage was not recovered and the pilot is presumed dead. The flight was en route from San Juan, Puerto Rico, to St. Croix, U.S. Virgin Islands, and was cruising at 7,000 feet. At about 04:53, the pilot requested a lower altitude and was cleared to 2,000 feet. The pilot acknowledged the clearance and no further transmissions were received from the pilot. Radar showed the aircraft began its descent, then a high-pitched tone was heard on the communications radio frequency. In the next 16 seconds, radar returns show the plane descending from 5,500 feet to 1,200 feet, when radar contact was lost. Debris and mail from the aircraft was located around the east end of Vieques.