In 1971, a magnitude 6.7 earthquake hit Los Angeles. One of the places that was hit by the earthquake was the Van Norman Dam. The dam crest dropped 30 feet during the earthquake. Only a ridge of dirt prevented the dam from collapsing and flooding the San Fernando Valley. Eventually, the crisis passed and a replacement dam was built.
The PoD is that the crest of the dam drops below water level. This causes the water to cut a deep channel through the dam that causes it to fail in an hour. The flood hits everything from the dam to the Sepulveda Reservoir.
Death toll and property damage, anyone? The death toll would be decreased by an hour's warning as people evacuated, but not everyone would get out of the area in time. (Note: 80,000 people were evacuated OTL.)
The PoD is that the crest of the dam drops below water level. This causes the water to cut a deep channel through the dam that causes it to fail in an hour. The flood hits everything from the dam to the Sepulveda Reservoir.
Death toll and property damage, anyone? The death toll would be decreased by an hour's warning as people evacuated, but not everyone would get out of the area in time. (Note: 80,000 people were evacuated OTL.)
