Because of low tide and other geographical factors, the San Francisco Bay Area escaped the wrath of the March 11 tsunami that formed following a 9.0-magnitude earthquake in Japan. But the rest of Northern California wasn’t so fortunate, as the waves that traveled 5,000 miles across the Pacific Ocean ripped apart three harbors, with Santa Cruz and Crescent City getting the brunt of the damage. Fort Bragg was also hit hard, as were six coastal communities. The total damage in California stands at about $40 million. Why is this developing story so relevant in San Francisco? Because it reminds us that the time is ripe for another catastrophic event like the earthquake that struck the city in 1906, according to the United States Geological Survey. The threat of a tsunami is much smaller, but we remain vulnerable to volatilities in the Pacific Basin. Since 1850, some 51 tsunamis have been recorded or observed in the San Francisco Bay, according to the Smithsonian/NASA Astrophysics Data System, with the 1960 Chili earthquake and 1964 Alaskan earthquake exacting the most damage. Both episodes lasted 12 hours. The 1964 quake caused $177,000 in damage to boats and other structures in the bay, which would translate to more than $1.2 million in 2011 figures, according to DollarTimes.com. Not much is known about sea disturbances formed in the 1906 earthquake, but we do know that a tsunami was observed at the Presidio tide gauge station in San Francisco, now located at Fort Point. Some possible follow-up stories: How would San Francisco fare in the next big earthquake? California officials held a joint state-federal exercise in November 2006 to re-create what would happen in just such a scenario. The estimates were more than 3,330 deaths, 13,000 serious injuries, 60,000 to 120,000 people requiring shelter and about $120 billion in building loses, according to FEMA. How would low-lying areas in Marin County, particularly Mill Valley, fare if the waves were high enough? What precautions do harbor areas in the San Francisco Bay take? What can we learn from Crescent City and Santa Cruz?