The tornado, classified as an EF-2 with an estimated maximum wind speed of 120 mph, hit around 3:38 a.m.
It had a path 50 yards wide and 6.2 miles long, the weather service said.
It was earlier classified as an EF-1, but the weather service later upgraded its assessment.
Officials said at least a dozen buildings were seriously damaged in the storm around the Laurel and Seaford areas.
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The Laurel Fire Department was dispatched to multiple calls following the heavy winds and rains that caused downed trees, road closures, and power outages.
Officials said the path of the damage stretched from west of Laurel to Georgetown, just north of the US Route 9 corridor.
Firefighters rescued a resident after a tree fell into a house.
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One person, an adult man, was taken to Nanticoke Memorial Hospital in Seaford with minor injuries.