impact Guam Ahead of the storm on August 25, the United States Department of Defense set the Condition of Readiness (COR) at stage 3 on Guam, indicating destructive winds were possible within 48 hours. A day later, the COR was raised to stage 2; all but two United States Navy ships were sortied from the harbor to prevent damage, and the remainder rode out the storm southwest of Guam. On August 28, COR 1 was declared, the highest level. In response, all fixed-wing aircraft and helicopters on the island were moved into hangars or transported to Japan or the Philippines. All schools were closed for the duration of Omar's passage over Guam. Flight operations were suspended for at least two days, stranding 5,000 passengers on the island. About 3,100 people rode out the storm in emergency shelters. Omar was the strongest and most damaging typhoon to hit Guam since Typhoon Pamela in 1976. The typhoon was felt on all parts of Guam; tropical-storm-force winds affected the island for 16 hours, and wind gusts were estimated to have reached 248 km/h (154 mph) in areas beneath the western eyewall. However, the high winds caused the anemometer at Hagåtña to fail during the eye's passage, and the radar at Andersen Air Force Base was lost, preventing accurate wind speed assessments. The lowest barometric pressure was at Apra Harbor. Omar's slow movement resulted in prolonged heavy rainfall, peaking at at the Guam National Weather Service Office in Tiyan and reaching 417 mm (16.41 in) at Andersen AFB. Damage on Guam was heaviest from the central region to the northern coast, in particular to tourist areas and military bases. The Naval Computer and Telecommunications Area Master Station was shut down due to power outages and water damage to the generators. Two US Navy ships, the USS Niagara Falls (AFS-3) and the USS White Plains (AFS-4)—both naval supply ships—went aground due to rough seas and strong winds, and the dry dock at Apra Harbor was washed ashore. Omar destroyed dozens of businesses on the island. High winds knocked a crane into an apartment building and downed 400 wooden and 20 concrete power poles across Tumon, leaving 70% of the island without power. Throughout Guam, Omar disrupted transportation and communication systems, and led to the failure of water pumping systems. Landslides covered roads, and low-lying areas were flooded. About 2,000 homes were destroyed and another 2,200