assignment among the thousands so far established has approached this one in the length, complexity, and thoroughness of the consideration that has been accorded in adjudicatory and rulemaking proceedings before the Commission, and in repeated judicial reviews." In March 1941, with the implementation of the North American Regional Broadcasting Agreement (NARBA), most of the original "clear channel" stations were reassigned to comparable authorizations. The FCC attempted to give KOB an assignment that would allow it to use high power to serve a large area of the underserved southwestern United States. KOB's initial 1941 NARBA assignment was for operation on 1030 kHz. However, another high-powered station, WBZ in Boston, Massachusetts, was also assigned to this frequency; moreover, WBZ employed a directional antenna that strengthened its signal westward. The resulting nighttime interference between WBZ and KOB caused the FCC, beginning later in 1941, to reassign KOB to 770 kHz with the first of a series of temporary Special Service Authorizations. The joint assignment of KOB and WABC to 770 kHz still resulted in interference over large areas of the middle of the country. The FCC later concluded that KOB and WABC should have equal status on 770 kHz as "Class I-B" stations, with both required to protect the nighttime coverage of the other station, and ordered that KOB and WJZ both install directional antennas. KOB constructed the required nighttime directional antenna, but WABC refused to comply, appealing the order in the courts. WABC's challenge was successful, primarily on the grounds that downgrading its coverage left its ABC network at a disadvantage compared to the other two national networks' New York City stations, CBS's WCBS and NBC's WNBC, which were non-directional operations. The FCC then reclassified KOB as a "Class II-A" station, and its directional antenna was modified to further reduce its signal toward WABC. Hot air balloon accident On October 9, 2004, a Smokey Bear imaged hot air balloon participating in the Albuquerque International Balloon Fiesta collided with and became entangled in one of KKOB's transmitter towers. The three passengers were able to climb out of the basket onto the tower. However, the tower was energized and could have led to electrocution once the passengers set foot on ground, so KKOB shut down its transmitter following the accident in order to enable them to climb down to safety. This accident was recorded by several local television stations, and the footage has become