DENVER (AP) — Authorities have begun assessing damage after a powerful, slow-moving storm skipped through eastern El Paso County for more than three hours on Thursday, damaging homes and cars.

The National Weather Service says a rare, backwards-spinning tornado was observed south of Ramah. Forecasters say giant, damaging, wind-driven hail, up to the size of tennis balls, was reported.

Five inspectors were sent from Denver on Friday to check damaged buildings.

Elbert County officials reported one minor injury and damage to eight houses, including two that were missing roofs and others with broken windows.