The Long Beach earthquake, estimated magnitude 6.25 Ms, occurred at 5:55 p.m., March 10, 1933.  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 catastrophically.  If the earthquake had struck a few hours earlier, when school was in session, the loss of life would have been appalling.  As it was, 120 people died in the quake largely from collapsed houses and small buildings or falling debris, including 5 children who died in failed gymnasia.

The school buildings damaged or destroyed were of an "irregular shape," built of brick and not designed to resist any lateral stress.  As well, part of the failure of the brick buildings was 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.

Franklin Junior High School before and after the 1933 earthquake.  Photos:  Historical Society of Long Beach

As a direct result of the structural failures of unreinforced masonry schools, earthquake-resistant design and construction were mandated for public schools:  K-12 and community colleges. This was due largely to the efforts of California Assembly Member,  Charles Field, and the law known as the Field Act was passed on April 10, 1933.  It and its subsequent revisions authorized the Division of Architecture of the California State Department of Works to review and approve all public school plans and specifications and to furnish general supervision of the construction work.  No Field Act school has ever failed in an earthquake.

The Uniform Building Code (UBC) of 1927 had addressed the first comprehensive earthquake code requirements for buildings in general in California.  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:

Long Beach was also the first earthquake for which acceleration records were obtained from the recently developed strong-motion accelerograph, but the accelerations exceeded the range of the first instrument.

Jefferson Junior High School - After

The Young Hotel (Compton, CA) - After

There was no surface rupture associated with this earthquake, which occurred on the Newport-Inglewood fault zone, a system of right-lateral strike-slip faulting.  It resulted in 120 deaths and over $50 million in property damage.  Most of the damaged buildings were of unreinforced masonry.  Many school buildings were destroyed; fortunately, however, the children were not present in the classrooms.