A locking apparatus for a rollup door, comprising a striker member, latch assembly including a latch, a release lever, a trigger, a cam and a solenoid. The latch assembly may also include a limit switch for detecting when the latch assembly is in an unlocked position. The locking apparatus can be electronically unlocked or it can be unlocked manually by a user by actuating the solenoid which causes the latch to release the locked striker member.