Residents, given sufficient warning, took to makeshift shelters around the city.

With sufficient warning, satellites can be turned around so their shielding faces the eruption, or switched to a lower voltage, and power can be rerouted from parts of electricity grids.

Unlike many of the affected areas, the town had received sufficient warning and most all who were in danger were able to move to safety.

To detect low-flying aircraft at a range allowing sufficient warning, a high-frequency system for radar picket ships 100 mi offshore was needed.

There had been reported examples of the warning lights operating incorrectly prior to the accident, including the lights failng to activate or activating without sufficient warning time.