It does seem like an occurrence policy should cover products manufactured during the policy period even if the damage/injury occurs later but thats not what the policy language states.
Why Do Earthquakes Happen? Earthquakes are usually caused when rock underground suddenly breaks along a fault. This sudden release of energy causes the seismic waves that make the ground shake. When two blocks of rock or two plates are rubbing against each other, they stick a little. They don't just slide smoothly; the rocks catch on each other.