Clintonville, Wisconsin residents say their homes rattled after explosion like noises awoke them.
And city leaders are still trying to find out what caused it all.
Some residents recalled hearing a loud boom around nine o'clock Sunday night.
Around between two–and three o'clock this morning...police phone lines were jammed with calls from a 13–block area.
Callers reported not just hearing loud booms but rumbling in the ground that shook some right out of their homes.
After checking out possible gas leaks in utility and storm sewers, officials says nothing out of the ordinary has been discovered.