Lockdown incident

From Lostpedia

In the episode "Lockdown", the blast doors descend, sealing off the living quarters from the rest of the hatch. After a short while, the doors retracted back into the ceiling automatically. This event has become known as the lockdown incident.

Chronology of the lockdown incident

John Locke, halted by the descended blast door during the lockdown incident

A garbled message by a female speaker, ending in a countdown to zero, was broadcast through the station's speaker system. The female voice (played by Lynnanne Zager) said: "23 minutes to lockdown"; "17 minutes to lockdown"; "Please proceed...protocol...please proceed..."; "9...8...7...6...5...4...3...2...1".

The garbles and "messy" counting could be explained by Radzinsky, Kelvin, and Desmond. When they faked lockdowns, they damaged the electronics inside.

The blast doors descended (but not in unison), sealing the living area of the bunker. The power was then disrupted as the lights flickered. When the countdown timer reached zero without completing the unspecified protocol, the lights went out entirely and a mechanical "revving up" sound could be heard. A different set of ultraviolet 'black' lights that ran vertically along the corners of the bunker illuminated what appeared to be a color-coded map of the Island on one of the blast doors. The counter then reset to 108 as the power returned about 20 seconds later and the blast doors retracted into the ceiling.

At approximately the same time as the lockdown, a large pallet of DHARMA-branded provisions landed by parachute, with a flashing beacon, near the entrance to the bunker. This appeared to be a restocking procedure and may have been connected to the lockdown. As seen on the blast door map: "ACTIVITY MINIMAL DURING LOCKDOWN AND RESTOCKING PROCEDURES".

The blast doors that descended were the door that shuts off the bunk beds, the door thats shut off the "window" next to the dining booth, the two doors of the computer room, and the door leading to the corridor.

The voice was first heard 23 minutes before the lockdown, the timer at this point had just over 47 minutes left; therefore, when the blast doors came down, there were just over 24 minutes remaining, meaning that the blast doors were down for about 24 1/2 minutes.

Other lockdown incidents

Desmond triggers a Lockdown for his first time by briefly shorting two power supply wires in his flashback in Ep. 2x23-24 "Live Together, Die Alone".

Kelvin says Radzinsky was the one who first figured out how to force a lockdown.
Kelvin and Desmond regularly tricked the system in to forcing a lockdown to work on the blast door map. ("Live Together, Die Alone")
Desmond forced a lockdown to lock Eko out of the room so that he and Locke could intentionally let the countdown timer reach zero. ("Live Together, Die Alone")