Cabin Pressure

The seven crew members of the space shuttle Challenger probably remained conscious for at least 10 seconds after the disastrous Jan. 28 explosion and they switched on at least three emergency breathing packs, the National Aeronautics and Space Administration said Monday.

A Mexicana Airlines Boeing 727, en route to Los Angeles from Mexico City with Easter holiday travelers, crashed and burned Monday in the mountains west of the Mexican capital after the craft apparently lost cabin pressure and the pilot made an emergency descent. All 166 people aboard were reported dead.