The explosion happened on Saturday morning in Plantation, west of Fort Lauderdale in Broward County, sending large pieces of debris about 100 yards across the street.
The fire department called it a gas explosion with "multiple patients".
Plantation police tweeted: "All stores and businesses in the area of the Fountains Plaza and the Plantation Marketplace plaza near LA Fitness will be shut down until further notice until fire personnel can determine that it is safe to return. Please do not come into this area if possible."
Other nearby shops were understood to have sustained damage.
Fire departments from Plantation as well as Coral Springs, Lauderhill and Davie all responded to the explosion.
An employee at a gym in the complex told local news station NBC6 she thought she could smell gas earlier in the morning.
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