Irma's winds knock down two cranes in Miami

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   Two cranes collapsed Sunday in Miami as Hurricane Irma's powerful winds lashed southern Florida, and officials warn there could be more such incidents given the area's building boom and the intensifying conditions.

The first crane, which came crashing down, was next to the federal prison in front of the courthouse Strong wind gusts ravaging the city could cause more cranes to collapse as Irma marches up the state's west coast.