The Purge is an event that happened on December 22, sometime between the late 1980's-early 1990's. After a long conflict between the Dharma Initiative and the Hostiles. The Hostiles released a toxic gas at the Barracks, killing all the members of the Dharma Initiative. Ben, who was originally part of Dharma, joined the Others, and ended up killing his own father, on Ben's birthday.

According to Mikhail, who at the time lied about being part of the Dharma Initiative, said that Dharma started a war against the Hostiles. He said that they took control of the submarine, and made a deal with him to stay in the Flame, as long as he does not cross the line.

When Ben talked to Locke about the Purge, he claimed that the two sides could not get along, and one had to go. He showed him a mass grave, where all the members of the Dharma Initiative were dumped.

Questions:

• Assuming they knew about it, why didn't anyone from the Dharma Initiative off the island retaliate?
• Did any Dharma members survive?
• Why are there still supply drops?