(CNN) Mike Karbo's neighbor woke him up about 10:30 p.m. Tuesday, asking for his help rescuing two people from a collapsed garage. But Karbo, information director for the town of Burke, South Dakota, said that was only the beginning of the damage from a tornado that rolled in overnight.

The town's Building Center and lumberyard were flattened by the storm.

Karbo said the storm ripped through the center of town, splitting it in half. When the sun rose on Burke on Wednesday, its 600 or so residents discovered that the civic center and the building that contains the high school and middle school were destroyed, as were some homes in the county.

A severe thunderstorm warning was issued for Gregory County about 25 minutes before the storm hit, but there were no tornado watches or warnings. CNN Weather confirmed that an EF1 tornado touched down, with wind gusts up to 110 miles per hour. The National Weather Service in Sioux Falls, South Dakota, is assessing storm damage.

On Wednesday, crews worked to clear roads and restore power to the half of residents who were in the dark.

The building that houses the high school and middle school was leveled.

Despite the damage, only the two people trapped in the garage were hurt, and their injuries were not life-threatening, Mayor Tom Glover told CNN affiliate KSFY.

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