A building that has been damaged and did not fall has not proved that it will not fall. Structures come down hours and days later, routinely.
Do not go back in for possessions. This is where a very large share of avoidable deaths after an incident happen.
Signs to treat as evacuate-now: new cracks, especially wide or diagonal ones; doors and windows that no longer close; visibly sagging floors or ceilings; the sound of creaking or settling; dust falling from a ceiling; a smell of gas.
Assume services are damaged. Do not switch anything on. Do not use a naked flame. If you smell gas, do not operate a switch or a doorbell — the spark is the ignition source — leave and tell somebody from outside.
Water damage undermines things quietly. A floor that was flooded may not hold.
A building is safe to re-enter when somebody qualified says it is, and not when it looks all right.