The crew forgets to extend flaps, the MD-82 crashes right after takeoff

What happens in this video ?

Video of the Spanair MD-82 accident in Madrid, Spain, on August 20th 2008. The video was recorded by airport cameras. It shows the aircraft accelerating on the runway to take off. Its wheels are barely off the ground when it crashes in a cloud of smoke and flames. 154 people were killed, and 18 people escaped alive.
Click hereafter for more details about this event.