It is hard to imagine any people, collectively, being better prepared for earthquakes than the Japanese. Their country is one long seismic zone, which at any moment could, literally, rock and roll. Every Sept. 1, across the archipelago, Japanese engage in exercises devoted to disaster awareness: what to do should the worst happen. The occasion resonates with history. On that date in 1923, the Great Kanto earthquake devastated Tokyo and nearby Yokohama, unleashing fire and fury that left more than 100,000 people dead. After that, Japan resolved that it would prepare for whatever cataclysm nature might throw at it.

And yet.

When a huge earthquake struck Kobe in southern Japan in January 1995, killing more than 6,400, the national government and local officials stood accused of foot-dragging — a slow response that, among other failings, cost some people their lives and left as many as 300,000 others out in the cold, homeless for far too long. Comparable indictments of the authorities were heard in 2011 after the Tohoku earthquake and tsunami, which overwhelmed parts of northeastern Japan and created the enduring nuclear nightmare at the crippled Fukushima Daiichi power plant.

Readiness, or lack of it, is also on the national mind in this country after back-to-back earthquakes rocked Southern California in late March. Damage was relatively slight. But a question that had loomed for decades suddenly gained new urgency: How prepared are Americans, especially Californians, for the anticipated killer quake routinely referred to with a mixture of dread and awe as the Big One? That question is the focus of the latest installment of Retro Report, a series of video documentaries that hark back to major news stories from the past, and examine what has happened since.

The starting point for this week’s offering is the Loma Prieta earthquake that jolted the San Francisco Bay Area on Oct. 17, 1989. Named for a mountain peak south of the bay that was near the epicenter, the 6.9-magnitude temblor killed 63 people, 42 of them when the upper level of a double-deck portion of freeway in Oakland collapsed and crushed cars below.