Imagine sitting at your kitchen table when the floor starts to roll like the ocean. For millions of people this morning, that nightmare became a reality.

WHAT HAPPENED

At 8:10 a.m., a 5.6 magnitude earthquake struck a rural part of Northern California. The ground shook so hard that people felt it hundreds of miles away in Oregon and Nevada.

Phones buzzed with loud warnings telling people to "drop and cover." While the center was in a quiet area, the shockwaves reached major cities across the West Coast.

Teams are now out checking roads and power lines for any cracks or breaks. So far, no one has been reported killed in the event.

WHAT THE EVIDENCE SHOWS

*Strength: 5.6 magnitude.

• Time: 8:10 a.m. Pacific Time.
• Reach: Felt in California, Oregon, and Nevada.
• Alerts: Millions of emergency phone notifications sent.
• Deaths: 0 reported as of Wednesday morning.

THE BIGGER QUESTION

We spend billions of dollars on early warning systems and building rules. Did those systems actually save lives today, or were we just lucky the quake hit a rural area?

If this same shake happened under a major city, would our homes and bridges still be standing? This is a wake-up call to check if we are truly ready for the "big one."

WHAT HAPPENS NOW

Crews will spend the next few days looking at bridges and dams for hidden damage. People in the area are cleaning up fallen items and checking on their neighbors.

Expect to hear more about aftershocks over the next week. For most people, life will go back to normal, but the fear of the next shake will linger.

WHAT WE STILL DON'T KNOW

1. How much will the total repair bill be for the affected towns?
2. Are there larger aftershocks coming in the next 48 hours?
3. Did any remote roads or water lines suffer damage that hasn't been found yet?