The Crisis Tower is a technological construction created by Krang. Its purpose is to merge the progenitor worlds of both the Ninja Turtles and Batman, allowing Krang to reshape their multiverses into a new one controlled by him. The exact mechanics are not explored, but it is mentioned that Krang obtained technology from the cosmic beings of Batman's dimension, including the Anti-Monitor.
Krang captured both the Turtles and Batman, and placed them on the Crisis Tower. When activated, the tower began electrocuting the five individuals, until they broke free and escaped down into its corridors.