Washington: All the seven astronauts on board the Columbia space shuttle including the first ever Indian-origin woman astronaut Kalpana Chawla were killed on February 1 when the space vehicle broke in flames at a height of 63,000 metres over Texas, 16 minutes before it was due to land.

American officials, on condition of anonymity, said the worst has befallen on the crew that included five Americans and the first-ever Israeli astronaut.

The first indication of the worst being feared came when the US flag next to NASA (National Aeronautics and Space Administration)'s countdown clock and at the White House was lowered to half-mast within two hours after the news of the shuttle disaster came.

PTI