1983 Coalinga Earthquake - Damage and Casualties

Damage and Casualties

This earthquake caused an estimated $10 million in property damage (according to the American Red Cross) and injured 94 people. Damage was most severe in Coalinga, where the 8-block downtown commercial district was almost completely destroyed. Here, buildings having unreinforced brick walls sustained the heaviest damage. Newer buildings, however, such as the Bank of America and the Guarantee Savings and Loan buildings, sustained only superficial damage. The most significant damage outside the Coalinga area occurred at Avenal, 31 kilometers (19 mi) southeast of the epicenter.

A disaster assessment by the American Red Cross listed the following statistics on damage in the area: almost destroyed - 309 single-family houses and 33 apartment buildings; major damage - 558 single-family houses, 94 mobile homes, and 39 apartment buildings; and minor damage - 811 single-family houses, 22 mobile homes, and 70 apartment buildings. Most public buildings, including the City Hall, hospital, schools, fire house, post office, and police station, sustained only minor damage.

Only six bridges of 60 surveyed in the area sustained measurable structural damage. This damage consisted of hairline cracks and spalling at the top of the support columns, fracturing and displacement of wing walls and parapets, and settlement of fill.

All public utilities were damaged to some degree. The water system continued to function despite many leaks in its transmission piping. Gas was shut off for several days because of broken piping and leaks, but only temporary interruptions of electric and telephone services were reported. One large section of old concrete sewer pipe west of the downtown area partly collapsed, but this system also continued to function.

In the oil fields near Coalinga, surface facilities such as pumping units, storage tanks, pipelines, and support buildings were all damaged to some degree. One oil company administration building, about 7 km (4.3 mi) north of Coalinga, sustained major structural damage and its two brick chimneys were toppled. Subsurface damage, including collapsed or parted well casing, was observed only on 14 of 1,725 active wells.