On September 7, 1977, the U.S. Consumer Product Safety Commission issued a public warning, urging carnival-goers not to ride the Zipper after four deaths occurred due to compartment doors opening mid-ride. The safety restraints being attached to the door itself, riders are left unrestrained whenever the door is open. The four victims all died after falling from their compartments. The failure was traced to original spring-close latches on the doors wearing out and not being replaced. Compartments on currently operating Zippers are secured using the original latch, a redundant latch approved by the CPSC, and a large R-Key pin as a second backup.