A passenger jet bound for London crashed today in western India only moments after takeoff, killing more than 260 people. It was India’s worst aviation disaster since 1996.

One passenger was known to have survived the crash, according to India’s home minister. “I don’t know how I am alive,” the passenger, Viswash Kumar Ramesh, said, according to his younger brother.

The plane, which had been carrying 242 passengers and crew members, crashed into a medical college in the city of Ahmedabad and killed several people on the ground. As night fell and smoke hung in the air, rescuers combed through the smoldering wreckage.

It was not immediately clear what had caused the plane, a Boeing 787 Dreamliner, to crash. The Dreamliner has been under scrutiny for years, but had never been involved in a fatal crash.

Video verified by The New York Times shows the plane taking off and then descending slowly over a cluster of buildings before a large fireball erupts on the horizon. It was in the air for less than a minute. In the video, the plane’s position looks as if “it should be climbing, and in fact it’s descending,” a safety consultant and former airline pilot told The Times. “The question is why.”

For more: Here’s a map of the crash.