passengers and all crew members were held by North Korea and to date have not been permitted to return. See Korean Air Lines YS-11 hijacking. On October 12, 1970, two KPA guards and one KPA officer approached a group of UNC guards. The KPA soldiers attempted to remove the MP brassard from one UNC guard; a shoving match ensued. The KPA guards disengaged, moved to the KPA Joint Duty Officer building and returned with approximately 30 KPA guards and workers. Armed with shovels, clubs, and rocks, the KPA workers initiated a mêlée. One UNC guard was isolated from the rest, dragged between the MAC and JDO buildings, and beaten on the head with a shovel. Shortly afterward 50 unarmed UNC guards from the UNC JDO building arrived and joined the fray and began isolating and disabling KPA guards on the UNC side of the MDL. Fighting ceased when two KPA guards emerged from a guard post armed with AK-47 rifles. Seven UNC guards suffered injuries, including one with a skull fracture. On September 22, 1971, the first hotline between North and South Korea became operational to allow the North and South Korean Red Crosses to negotiate. More direct phone lines were established throughout the 1990s and 2000s until there were 33 hotlines that run through the Panmunjom area. On March 3, 1974, a KPA officer and two KPA guards approached a UNC-sponsored tour at UNC Observation Post 5 (now UNCP #3). The UNC escort officer prevented the KPA group from harassing the tour group, at which point the KPA officer grabbed the UNC officer's shoulder. At the same time one of the KPA guards kicked the officer in the back and groin. Approximately 25–30 KPA personnel moved to the site and isolated the UNC officer, preventing him from returning to UNC Check Point 4 until the UNC Quick Reaction Force arrived on scene and dispersed the KPA soldiers. After the UNC QRF departed with the injured officer, KPA guards returned, broke into Check Point 4 and began to vandalize the interior. The QRF redeployed to Check Point 4 and forced the KPA away. The KPA responded by sending approximately 100 additional soldiers to KPA Guard Post No. 7 at the west end of the Bridge of No Return. The UNC JDO arrived on the scene and prevented an escalation by proposing an immediate Security Officers' Meeting. However, upon withdrawing from