NPR just reported we lost contact with the space shuttle Columbia. Our prayers are with the crew.

UPDATE:

The shuttle was seen breaking up over Texas.

UPDATE:
NASA Loses Contact With Space Shuttle Columbia (THE ASSOCIATED PRESS, February 1, 2003)

NASA declared an emergency after losing communication with space shuttle Columbia as the ship soared over Texas several minutes before its expected landing time Saturday morning.

Fearing the worst, NASA ordered flight controllers to pull out emergency procedures and ordered them to retain all their records.

Columbia was aiming for a touch down at 9:16 a.m.

It was at an altitute of 200,700 feet, traveling at 12,500 mph when mission control lost contact. There was no further communication and no further tracking data. [...]

Ilan Ramon, a colonel in Israel's air force and former fighter pilot, became the first man from his country to fly in space, and his presence resulted in an increase in security, not only for Columbia's Jan. 16 launch, but also for its landing. Space agency officials feared his presence might make the shuttle more of a terrorist target.

Here's the NY Times story on the Apollo One fire:
3 Apollo Astronauts Die in Fire; Grissom, White, Chaffee Caught in Capsule During a Test on Pad (The Associated Press ,
1/27/1967)