Today marks the 25th anniversary of the massive earthquake that hit the San Francisco Bay Area just before Game 3 of the 1989 World Series. Bob Ley talks with former A's pitcher Dave Stewart, and Dr. James Betts about their experience that day. (6:58)

They used to play an evacuation video before every Giants game at Candlestick Park. On the hazy, small, barely visible scoreboard screen, arrows urged spectators toward their "orderly line" of safety in the unlikely -- they always included the word "unlikely" -- case of an emergency.

In California, while driving on bridges or walking under overpasses or sitting in enormous structures like Candlestick, we know there's really only one kind of emergency: earthquake. We have become walking seismometers, able to feel a tremor and immediately dismiss it as a "3" or a "2," as unworthy of serious concern as a romance novel. And when it hits like thunder and pitches side to side -- as it did when a 6.0 woke my town in the dead of night on Aug. 24 this year -- we know the difference. For a few seconds, as the house creaks and rocks and the street lights sway, the unthinkable becomes possible: Is this The Big One?

At 5:04 p.m. Pacific time, 25 years ago, this happened in the Bay Area. Jonathan Nourok/AFP/Getty Images

As someone who grew up in the Bay Area and spent quite a few frigid summer nights in Candlestick, I generally ignored the specifics of the evacuation video. But I can remember looking at the impressive amount of concrete spread out in all directions -- especially the sweet scalloped overhang ringing the upper deck -- and wondering what would happen if it all folded in on itself. Unlike Nebraskans who seem to accept tornado warnings as a fact of life, Californians shove earthquakes to a distant corner of the brain. We think about them only when they are happening or when someone -- the Candlestick Evacuation Video Crew, for instance -- brings them to our attention.

But then there we were, watching the opening to the third game of the 1989 World Series on television, when Tim McCarver started recapping Dave Parker's drive into the right-field corner in Game 2 and how Candy Maldonado hesitated before throwing late to second base while Jose Canseco crossed home plate with a run. Even now, watching it over, knowing everything we know about what happened immediately afterward, the temptation is too great:

Wait a second. Did Jose Uribe's tag get there ahead of Parker? Was he really safe? Would that have changed anything?

And then something weird happens to the feed and you're driven back into reality. The picture is beginning to break up as Al Michaels cuts in and says, "I'll tell you what ... we're having an earth ..."