Residents across Northern California's coast were told to quickly evacuate Thursday morning and urged to seek higher ground after a magnitude 7 earthquake off the coast of Humboldt County prompted a tsunami warning.
The alert just before 11 a.m. warned that "a tsunami with damaging waves and powerful current is possible."
But about an hour later, the alert was canceled.
It felt to some like emergency whiplash. Others were left confused.
But officials say that they followed the correct protocol to respond to a potentially dangerous tsunami and that it was necessary to provide residents adequate time to reach safety.
"Time has to be respected to get people safe," said Dave Snider, the tsunami warning coordinator at the National Tsunami Warning Center in Alaska.
“The No. 1 challenge with tsunamis is we know a large event has happened," Snider said of the earthquake. "We don’t know if a tsunami is actually occurring."
Given the size and location of the earthquake, his team immediately kicked into action their procedures for a potential tsunami, and the first step is to issue as targeted a warning as possible.