The Monolith Monsters (1957)

A strange black meteor crashes near the town of San Angelo and litters the countryside with fragments. When a storm exposes these fragments to water, they grow into skyscraper-sized monoliths which then topple and shatter into thousands of pieces that grow into monoliths themselves and repeat the process. Any humans in the way are crushed or turned into human statues. The citizens of San Angelo desperately try to save themselves and the world from the spreading doom.