BBC Verify analyses moments before Washington DC plane crash
Investigators have recovered the flight data recorders, also known as black boxes, from an American Airlines jet which collided with a US army helicopter above the Potomac River near Washington DC.
All 67 people aboard the two aircraft were killed in the accident.
BBC Verify's Nick Eardley has been taking a closer look at what we know so far about the circumstances leading up to the collision.
Produced by Jemimah Herd
Motion graphics by Mark Edwards