If it's any consolation, there's not really time to escape a collapsing building from any level, since the bottom floors usually are crushed first and near instantaneously. If you look at pictures from partially collapsed buildings in Hualian you can see that sometimes it's just the bottom floor that's destroyed and the remaining floors are fine for sometimes days or even until the building is manually taken down.

The pictures of collapsed buildings after earthquakes are scary but the chance of an individual building collapsing are quite low, you're at far greater risk if you're outside near buildings because broken glass or similar could fall on you.

The standard advice is good advice for a reason: stay inside, under sturdy furniture, on your elbows and knees, covering your head. You can learn more here: https://sf-fire.org/disaster-preparedness-information-resour...