B737-300
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
Flight Crew Diverted; General Declared Emergency
Aircraft
Level cruise at FL250; left pack inoperative; on MEL. Cabin altitude warning horn sounded. [We] noticed cabin at or near 10;000 FT and climbing. We donned oxygen masks and I requested lower altitude as the First Officer started the QRH procedure. He could not control the cabin so we declared an emergency and started an emergency descent to 10;000 MSL. We diverted to a nearby airport as a precaution and landed uneventfully[I] was told of several bad door seals and a slightly misaligned left rear door.We need to fix packs sooner and pay more attention to door seals.
A B737-300 suffered a loss of pressurization; declared an emergency; initiated an emergency descent and diverted to a nearby airport as a precaution.