(CBS) – Drivers in flood-fatigued Gurnee are going to have to find an alternative route for a while.

A giant crater opened up Thursday morning on Gages Lake Road near Lonard Drive.

A spokesperson for the Lake County Department of Transportation blames the collapse on rusted pipes under the road. No word yet how long repairs might take.

Meanwhile, the river was expected to crest Saturday in the far north suburb.

Volunteers and village employees spent a sunny, humid day Thursday filling sandbags.

Every time the sandbaggers stopped to wipe their brows, they see the river creeping up at the edge of Warren Township High School’s north parking lot.

The lot they are using to shovel the bags full could be underwater itself in 24 hours.

Clemens Kyllmann brought his two sons and a young neighbor. He sees it as civic responsibility, as do many of the other volunteers.

Mayor Kristina Kovarik calls the flooding “epic” and says those who volunteer are welcome.

She says the flooding would have it far more quickly and caused far more damage, had the village not spent the past 10 years buying flood-prone properties and returning the wetlands to their natural state.