A vacant pizza restaurant exploded on Saturday in a thundering roar at a south Florida shopping plaza, injuring 21 people as large chunks of concrete flew through the air.
The blast flung debris widely along a busy road in Plantation, west of Fort Lauderdale. The restaurant was destroyed, and nearby businesses and cars were damaged.
Though firefighters found ruptured gas lines afterward, authorities said it was too early to determine a cause.
The explosion scattered large pieces of concrete as far as 50 yards and sent pieces of metal as far as 100 yards across the street.