Abstract: The invention relates to a safety latch assembly for a warehouse type door that has rollers riding in a vertical guide track, such track having latching holes at various points along its length. The latch assembly has a latch pin with a roller end spring biased toward the track, and rides on the track with the door until it comes into latching engagement with one of the aforementioned holes, and locks the door into its current position. Withdrawing the latch pin from the hole resets the bias spring as the door becomes unlocked.