A “squall line” blew a parked semi-truck onto a pickup truck Friday afternoon at Shelco Electric in Hermiston.

Strong wind gusts caused havoc in Hermiston on Friday afternoon, including a widespread power failure and property damage.

The windstorm, with speeds above 50 mph, knocked out power on a 115 kilovolt line transmission line serving Umatilla Electric Cooperative and Hermiston Energy Services at 2:08 p.m., temporarily disabling seven substations affecting 9,935 customers in Hermiston, Echo and Umatilla. By 2:41 p.m. Umatilla Electric Cooperative reported that power was “partially restored” and crews were continuing to work on the problem. By 4:30 p.m. spokesman Steve Myers said power was restored to all but 739 Hermiston customers, who were affected by a separate incident where a tree tore down wires near the Hermiston Butte. Those customers regained power shortly before 5 p.m.

According to the National Weather Service in Pendleton, wind speeds at the Hermiston Airport reached 53 mph at the front of the squall line. Several people reported seeing a tornado, but Mary Wister, the science and operations officer for the NWS, said none had been confirmed.

At Hermiston Cinema on Theater Lane, a wind gust blew the building’s HVAC system off the roof, dropping it on the gravel parking area on the north side of the building. Hermiston Fire & Emergency Services and Cascade Natural Gas responded after employees reported smelling gas.

At Shelco Electric a parked semi-truck blew over on its side, landing on a pickup truck. A Shelco employee said no one was in either vehicle when it happened. Hermiston Fire & Emergency Services assisted in cleaning up diesel leaking from the truck.

At Good Shepherd Medical Center a jumble of metal siding and debris stripped from the building landed on the south side of the campus. It looked calamitous, but spokesman Nick Bejarano described the damage as “all superficial” with no structural damage.

Guardian Angel Homes reported that they lost part of their roof to the gust, but the interior of the home remained intact and no one was injured. Their construction site for their new buildings also suffered damage, including broken windows, moderate siding damage and a destroyed fence.

Other Hermiston residents posted photos and descriptions on Facebook of damage to their property or workplace, including uprooted trees and missing shingles and gutters.