Workers in Madison had to repair at least four water main breaks since Sunday afternoon. Jim Gilchrist, a third-generation plumber in the Chicago suburb of Oak Park, said he received about five or six calls Tuesday from people with frozen water pipes in their homes. Few pipes had actually burst — yet.

‘‘We'll probably get those calls later, as pipes begin thawing’’ and develop a split, Gilchrist said. ‘‘Today they just know they don’t have water; tomorrow they will have water spraying.’’

At least two fires in southern Wisconsin were blamed on property owners using heaters or other means to thaw frozen pipes. In one case, a dairy barn was destroyed, and in the other, a mobile home was lost. No one was hurt.

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