In accordance with the Swissair checklist 'In case of smoke of unknown origin', the crew shut off power to the cabin, which also turned off the recirculating fans in the cabin's ceiling. This allowed the fire to spread to the cockpit, eventually shutting off power to the aircraft's autopilot. At 22:24:28 AT (01:24:28 UTC), the crew informed Halifax that "we now must fly manually", followed by declaring an emergency. Ten seconds later, the crew declared an emergency again, saying "...and we are declaring emergency now, Swissair one eleven"; this was the last transmission received from Flight 111.