It happened just before noon on Main Street in East Orange, with the fire truck careening into a building after the initial collision.
Three firefighters on board the truck and the drivers of the two other vehicles -- a man and a woman -- were taken to the hospital.
There is no word on their condition or what led to the crash, though officials believe the injuries to be minor.
The extent of the damage to the building is also unclear.
Preliminarily, officials said it appears the fire truck was on the way to a call, and that vehicles were pulling over or getting out of the way to let the fire truck pass.
The passenger car involved in the accident somehow got in the way, perhaps unaware of the situation, and it looks like that caused the accident.
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