The 1933 Long Beach Earthquake, The Field Act, And The Gap It Left Behind

California passed two earthquake laws in the spring of 1933, six weeks apart. One of them produced a public building stock with one of the better safety records in the country. The other set a standard so low it was already obsolete when the ink dried.

Almost everything about how a California property owner is exposed today traces back to the difference between them.

Some of what follows is building regulation, which belongs to engineers and city planning departments rather than to us. The part that is ours is the last third: what a building code is actually designed to accomplish, and why that leaves a bill somebody has to pay.

The argument that ended at dinner time

At 5:54 on a Friday evening, March 10, 1933, the Newport-Inglewood fault ruptured about three miles south of Huntington Beach. The California Geological Survey records a magnitude of 6.4, roughly $50 million in damage in 1933 dollars, and 120 deaths, most of them caused by unreinforced masonry buildings coming apart.

Seventy schools were destroyed and 120 damaged, about 75 percent of the schools in the area. Children and teachers had gone home hours earlier. The state’s own assessment is that had the earthquake arrived during the school day, casualties would have been in the thousands.

The buildings that failed worst were the ones the state had just missed filling with children.

The earthquake also settled a scientific argument, and that argument had shaped how Los Angeles was built. After 1906, concern in California focused on the San Andreas fault, fifty kilometers or more from the growing population centers. One school of thought held that the local faults underneath Los Angeles were not particularly active and would never produce severe shaking. March 10 ended that debate.

The Newport-Inglewood fault runs 46 miles on land, from Culver City down to Newport Beach, where it continues offshore. Inglewood gave it half its name. It is thought capable of producing an earthquake as large as magnitude 7.4.

For the first time, instruments recorded what that shaking actually did. The maximum recorded ground acceleration in 1933 was 22 percent of the force of gravity. Hold on to that number.

Twenty-eight days

The Field Act was signed by Governor James Rolph on April 10, 1933, twenty-eight days after the earthquake. Its author was Assemblyman C. Don Field, a Republican building contractor from Glendale who had watched buildings come apart and did not intend to watch it again.

What the Act created was not a slogan about safe schools. It was a procedure, and the procedure is the substance.

Licensed design professionals prepare the drawings. The Division of the State Architect must approve them before a construction contract can be awarded. The district hires a certified project inspector, approved by the owner, the designers and the state. Changes go back for approval before the work is done.

At the end, the designers, the inspector and the contractor each file verified reports confirming the building matches the approved plans. The Geological Survey notes those closing verifications are made under penalty of perjury.

Every step is a separate party attesting in writing to a document another party approved. It is an audit trail, imposed on construction, in 1933.

The state’s position is that there has never been a major structural failure or loss of life during a seismic event at a Field Act-compliant school. That is the state describing its own program, and the qualifier is doing real work in it. Even read conservatively, it is a remarkable ninety-three years.

The law nobody remembers

Six weeks later, the Legislature passed the other one.

The Riley Act was enacted on May 26, 1933. It required every local government in California to have a building department, which many did not. And it required that all structures be designed to withstand a horizontal acceleration of 0.02 times the acceleration of gravity.

Two percent. The ground in Long Beach had just moved at 22.

That is the split that shapes everything afterward. Schools got separate plan review, certified inspectors, perjury-backed verification and a state agency with authority to stop the job. Everything else, the houses and shops and apartment buildings, got a permit counter and a design floor an order of magnitude below what the instruments had measured.

The Riley Act was a genuine advance for its time. But the two laws were never equivalent, and California has spent the ninety years since working on the difference.

What happened to the buildings already standing

There is a second gap, and it is the one that still reaches property owners. The Field Act applied only to new construction. It said nothing about the school buildings already in use.

Closing that took four decades of follow-up legislation, from the Garrison Act of 1939 through the Greene Acts of the late 1960s, which finally attached deadlines. The Geological Survey records that as of 1974, all pre-Field Act schools in the Los Angeles area had been retrofitted.

The private building stock waited another twelve years. California’s main effort there is the URM Law of 1986, which required local governments in the highest seismic zone to inventory their unreinforced masonry buildings and establish loss reduction programs by 1990.

One piece of that law turns up in real transactions. Since January 1993, the seller of an unreinforced masonry building with wood frame floors or roofs built before 1975 has had to deliver a written notice to the buyer before the sale.

If you are buying an older commercial or apartment building in Los Angeles, that disclosure is not paperwork. It is the state telling you what the underwriter is about to ask.

Does a building code protect your property?

Not in the way most people assume, and this is where the history becomes a coverage question.

Every law above is a life safety program. In the State Architect’s own words, the Field Act’s design objective is that buildings resist the strongest earthquake anticipated at the site “without catastrophic collapse.” The standard allows for “some repairable architectural or structural damage.” Not without damage. Without collapse.

That is the correct goal for a law about where children sit. It was never meant to be a promise about anyone’s building.

A structure can perform exactly as the code intended, protect everyone inside, and still leave the owner with a repair bill.

That bill is what property insurance is for, except that earthquake sits outside the standard policy. California’s answer was not to include it but to require that it be offered.

Insurance Code section 10081 provides that no residential property policy may be issued, delivered or initially renewed in California unless the named insured is offered coverage for loss caused by earthquake. Where that offer is declined, it has to come around again every other year. If you have been setting the same letter aside each renewal, that is the statute at work.

One coverage speaks to this article directly. Up to $10,000 of building code upgrade coverage comes with a California Earthquake Authority homeowners policy, and limits of $20,000 or $30,000 can be purchased. It exists because a damaged home may need upgraded plumbing, electrical and mechanical systems to pass inspection, and generally has to be rebuilt to current code.

The condition attached matters as much as the limit. Under the policy form, the coverage applies where there is a covered loss above the deductible and you repair the property, and it reaches only the reconstruction costs attributable to the permit and approval process. The payment follows the repair rather than arriving in place of one.

We go through the rest of it on earthquake coverage, including how the two markets compare and why the deductible is a percentage. The same logic runs through commercial earthquake insurance, where retrofit ordinances are live obligations rather than history, and through the difference in conditions structure that carries earthquake for many California buildings.

Where this leaves a California property owner

California decided in 1933 that children would be protected by regulation, and that everyone else would be protected by a minimum standard and, eventually, the option to buy insurance. Those are different decisions, and ninety-three years later they still produce different outcomes.

The fault that did it runs from Culver City to Newport Beach and is thought capable of considerably more than 1933. Whether to carry earthquake coverage, and at what deductible, is yours to decide. What we can do is walk you through what your current policy excludes, what the two markets will write on a building of your age and construction, and where the code upgrade limits sit.

For the other half of this story, the one about what happened to the insurance market rather than the building code, see how the 1994 Northridge earthquake reshaped earthquake coverage.

Call the Granada Hills office at 818-322-4744 or request a review. Be insurance wise.

Statutes, program requirements and coverage limits described here are as published at the time of writing. The Legislative Counsel publishes the current text of each code section, and the California Earthquake Authority publishes current policy terms.

Sources

• California Geological Survey, The 1933 Long Beach Earthquake
• U.S. Geological Survey, M6.4 March 10, 1933 Long Beach, California Earthquake
• Division of the State Architect, AB 100 Report to the California Seismic Safety Commission, 2023. DSA counts damaged schools at 420 against the Geological Survey’s 120; the two appear to divide serious from minor damage differently.
• California Seismic Safety Commission, Status of the Unreinforced Masonry Building Law, 2006 Progress Report
• California Legislative Information, Insurance Code section 10081
• California State Library, The Children Are Spared, the Field Act Is Born

Disclaimer

This article is provided by Schneiderman Insurance Agency for general informational purposes only. It is not legal, tax, financial, claims, or coverage advice. We are licensed insurance professionals, not attorneys, accountants, or financial advisors, and nothing here should be relied on as a substitute for advice from a qualified professional in those fields. This content is general in nature and is not a review of, or a recommendation for, any individual reader’s specific insurance needs, policies, or circumstances. Insurance coverage depends entirely on the specific terms, conditions, endorsements, exclusions, limits, underwriting eligibility, carrier, and facts of each situation, and the actual policy language always controls. We do not guarantee any coverage, pricing, eligibility, underwriting approval, or claim outcome. Reading this article does not create an agent-client relationship. To understand how these issues apply to your situation, please review your own policy and speak with a licensed insurance professional, and consult legal, tax, or financial advisors where appropriate. Figures reflect research current to September 2026.