Springfield, IL- Fire department officials say they believe that heavy rains caused an underground electrical transformer to short out Monday morning.

The short out generated a lot of heat, causing insulation and other materials to burn. That produced a lot of thick black smoke which poured out of several manhole covers in downtown Springfield near the intersection of 4th and Washington. 

At one point there were some explosions as gas produced by the burning insulation ignited.

No fire fighters were injured. Traffic in the area was blocked until the fire was put out and the smoke cleared.

A few nearby businesses had their power shut off shortly, but that issue was resolved by mid-afternoon.

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