Impel Down Great Escape Incident

The Impel Down Great Escape Incident is an event that occurred when Monkey D. Luffy, leading the Prison Escape Team, led a mass breakout of the prison Impel Down. It marks the first and only time that a mass breakout occurred at the prison.

Origin
After hearing about Portgas D. Ace's pending execution, Monkey D. Luffy broke into Impel Down, intent on saving him. After an arduous journey, he reached Level 6 with Emporio Ivankov and Inazuma, only to discover that Ace had already been moved to Marineford; still dedicated to his task, he decided to set off for the Marine stronghold, freeing Jinbe and Crocodile to help him. The group began their ascent of the great prison, intent on fully escaping.

Event
The group, now called the Prison Escape Team, stormed up through the levels of the prison, freeing other prisoners as they went. They were joined by Bentham, Daz Bonez, Buggy, and Galdino, as well as many of the prisoners on Levels 1 and 2.

Despite attempts to stop them from Magellan, Hannyabal, and the Jailer Beasts, they were able to make it to the surface, where they commandeered a Marine warship. However, to open the Gates of Justice, Bentham needed to stay behind in the prison, sacrificing himself and remaining trapped.

Aftermath
Due to the Prison Escape Team's escape, they were able to participate in the Summit War of Marineford. Luffy's and Galdino's involvement nearly stopped Ace's execution, and Buggy's involvement broadcast the controversial strategies the Marines were willing to implement in the war. Luffy's presence in the war also revealed his relationship with Ace, as well as his relationship with Dragon and Garp, to the world.

Partly as a consequence of his supposed orchestrating of the event, Buggy joined the Seven Warlords of the Sea, founding Buggy's Delivery and hiring Galdino. Ivankov and Inazuma, joined by a multitude of newkama, returned to the Revolutionary Army, bolstering their fighting power. Crocodile and Bonez traveled to the New World, and after helping Luffy recover from Ace's death, Jinbe returned to Fish-Man Island.