Mysterious booms in Illinois
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Mysterious boom sounds in the middle of night have residents in Elgin tired and looking for answers.

Some residents say the booms are so loud, they even shake homes in the northwest suburb.

"The house shakes, the windows shake," said resident Colleen Roberg.

The noises have been heard at various hours of the day, but particularly overnight.

"They've become louder," said Sue Webb, president of the Southwest Area Neighbors group.

The SWAN group said residents have suspected two bridges as the possible cause of the booms - the Route 31 bridge that runs over Route 20 and the Route 20 bridge the crosses over the Fox River.

But the explanation still doesn't solve the mystery behind why some homes shake from the noise.

"We've had this since June and we've lived with the discomfort of it, but now we have our windows closed and it's really, really starting to irritate," said Webb.

There is also some railroad construction taking place below the Route 20 bridge, but that doesn't explain the noises in the middle of the night.

The Illinois Department of Transportation said it did an investigation, but didn't detect any loud noises from the bridges residents believe could be the cause. IDOT did take steps to notify the city about the surface conditions observed on the bridges, however.

The city of Elgin said it's investigating the cause of the noise, but can't confirm if the surface of the overpass is related at this point.

"We're just asking for solutions to our mystery boom," Webb said.

For now, the mystery remains unsolved.