1990 Luzon earthquake
The 1990 Luzon earthquake occurred on July 16, 1990 at 4:26 PM. The densely populated island of Luzon was struck by an earthquake with a 7.8 Ms (surface-wave magnitude). The earthquake produced a 125 km-long ground rupture that stretched from Dingalan, Aurora to Kayapa, Nueva Vizcaya as a result of strike-slip movements along the Philippine Fault Zone and the Digdig Fault. The earthquake epicenter was placed at 15º 42' N and 121º 7' E near the town of Rizal, Nueva Ecija, northeast of Cabanatuan City.<ref>The July 16 Luzon Earthquake, Philippine Institute of Volcanology and Seismology 2001</ref>
The earthquake caused damage in an area of about 20,000 square kilometers, from northwest of Manila through Central Luzon and into the mountains of the Cordillera Administrative Region. About 1,600 people were killed, mostly in the central Luzon and Cordillera region. This was one of the deadliest and costliest natural disasters in the Philippines.
Baguio City, a popular tourist destination, was one of the hardest hit areas with the number of deaths estimated at around 1,000. Several private and public buildings were severely damaged or destroyed, many of which were hotels. One of the buildings destroyed was a five-star Hyatt Hotel; one 12-story section collapsed over the lobby area killing about 50 people. The five-star Nevada Hotel was also damaged beyond repair when the lower level collapsed, killing about 40 people. Many affected residents who lost their homes ended up setting up tents in public parks such as in Burnham Park, or in the streets. Kennon Road, one of the major routes from Manila to Baguio City, was shut down due to severe landslides.
For the first 48 hours after the earthquake, the city was isolated from the rest of the country. Electric, water, and communication lines were destroyed. The city was inaccessible by land because of landslides and inaccessible by air, except to helicopters, because of damage at the airport. Food and fuel were scarce. Because hospital buildings were damaged, patients were relocated under tents set up in open spaces in front of the hospitals. Damage to homes and the occurrence of many aftershocks caused most residents to set up camps in open spaces in the city. Three days after the earthquake, a main road leading to the city was cleared to enable delivery of supplies. .<ref>International notes Earthquake Disaster - Luzon, Philippines </ref>
Cabanatuan City has many concrete buildings, but most of them are only three stories high. The only building that collapsed during the earthquake was Philippine Christian College, the tallest building in the city with six floors, trapping 274 students inside. All in all there were about 363 casualties, including 154 deaths. Rescue efforts were hampered by the lack of heavy equipment to cut through the steel reinforcement of fallen concrete. Agencies reported how some of the victims died not from collapsing infrastructure but from dehydration.
In Dagupan City, about 90 buildings in the city were damaged, and about 20 collapsed. Some structures sustained damage because liquefaction caused buildings to sink as much as 1 meter (39 inches). The earthquake caused a decrease in the elevation of the city and several areas were flooded. 47 were injured and 17 died. Most injuries were sustained during stampedes at a university building and a theater.
Five municipalities in La Union were affected: Agoo, Aringay, Caba, Santo Tomas, and Tubao with a combined population of 132,208. Many buildings collapsed or were severely damaged. 2,387 families were displaced when two coastal villages sank. The province suffered 493 casualties including 32 deaths.
- ^ The July 16 Luzon Earthquake, Philippine Institute of Volcanology and Seismology 2001
- ^ International notes Earthquake Disaster - Luzon, Philippines