Tectonic plates grind against each other for decades, moving mere millimeters a year. Friction holds them in place, acting like a tightly coiled spring. When the friction finally gives way, centuries of stored elastic strain energy are released in fractions of a second. The resulting seismic waves can level entire city blocks before the occupants realize the ground is moving.
// Clean up old damage entries outside the time window float now = Time.time; while (recentDamage.Count > 0 && now - recentDamage.Peek().timestamp > timeWindowSeconds) recentDamage.Dequeue(); destroyed in seconds
else if (currentHealth <= 0f)