1933 Long Beach Quake
TIME March 10, 1933 / 5:54 pm, PST
LOCATION This earthquake occurred on the Newport-Inglewood fault zone , three miles south of present-day Huntington Beach . There was no surface rupture associated with this earthquake.
HUMAN/PHYSICAL TOLLS 120 people died in the quake largely from collapsed houses and small buildings or falling debris, including 5 children who died in failed gymnasia. Engineered buildings and reinforced concrete buildings sustained little or no structural damage in the earthquake. Brick buildings with unreinforced masonry walls, including many of the school buildings in Long Beach and surrounding areas, failed, causing $50 million in property damage. Many school buildings were destroyed. Fortunately, however, the children were not present in the classrooms.
Above: The collapse of part of Jefferson Junior High School in Long Beach.
(Photo: Portland Cement Association)
LESSONS LEARNED School buildings that were damaged or destroyed were of an "irregular shape," built of brick and not designed to resist any lateral stress. Part of the failure of the brick buildings was also due to shoddy workmanship and inferior mortar. Several of the failed school buildings were designed with elaborate entrance towers that collapsed in a hail of bricks and architectural ornamentation. Reinforced concrete school buildings survived the quake with no structural damage.
This earthquake led to the passage of the Field Act, which gave the state Division of Architecture the authority and responsibility for approving the design and supervising the construction of public schools. No Field Act school has ever failed in an earthquake.
Building codes were updated. The 1935 version of the UBC, following the Long Beach earthquake and the legislative efforts to prevent school buildings from structural collapse provided a formula for calculating lateral earthquake forces which new buildings had to resist.
Sources: Southern California Earthquake Data Center and University of California at Berkeley.