Abstract: A revolving door including a plurality of door leaves extending radially outwardly from a center shaft in angularly spaced positions. The door leaves are mounted in a door opening for rotation about said center shaft by upper and lower bearing means. The door also includes upper and lower collapsing mechanisms which are adapted to normally maintain the door leaves in their radial positions, but to permit pivotal movement of each door leaf about the center shaft between its normal radial position and a collapsed position in the event that the door leaf is subjected to abnormal forces. One of the upper and/or lower collapsing mechanisms has associated with it a locking assembly having an electromagnet which normally is operated to prevent the collapsing mechanism from functioning so that the door leaves can be collapsed.