At least seven houses in Robscott Manor in Newark, Del., had structural damage and 40 more were hit by branches that did some damage, The Wilmington News Journal reported. The National Weather Service said a survey team would look at the damage to determine if it was caused by circular or straight-line winds.
WCAU-TV in Philadelphia said a photograph sent in by a viewer appeared to show a funnel cloud.
The storm downed trees and caused flooding and scattered power outages in the Wilmington and Philadelphia areas and in southern New Jersey. The NWS had tornado watches and warnings in place for much of the region.
Peggy Boyle of Newark, Del., told WCAU the storm at its height was terrifying.
"I laid down on the floor and then I looked and I saw the tree coming through the house," she said. "I just screamed."
The NWS in Mount Holly, N.J., told the News Journal the destructive winds that hit New Castle County appear to have been part of a narrow system that did not show up on gauges at official weather stations. Tornadoes are fairly common in the region although they tend to be much less violent than those in the central United States.