Severe thunderstorms rolled through parts of Butler and other counties Sunday, downing trees and power lines, knocking out electrical service, causing lightning strikes and sparking fires.

“We had a lot of calls for wires and trees down across the county,” said Steve Bicehouse, director of Butler County Emergency Services.

In neighboring Mercer County, a potential disaster was averted after a bolt of lightning started a fire at an assisted living facility near Grove City.

“Flames were shooting up from the roof pretty good when we got there,” said Chief Levi Hipps of the Pine Township Engine Company.

Staff and fire crews about 4 p.m. quickly began moving the mostly elderly patients at Orchard Manor to the wing of the facility farthest from the fire.

Authorities said 127 patients, including 10 who are bedridden, were moved to “safer ground” while crews battled the blaze.

The county, at Hipps’ request, immediately activated its mass casualty plan that, in part, sent 11 ambulances to the single-story facility in the event that someone had to be taken to the hospital.

No one had to be transported due to any injury or medical condition. Instead, patients were moved 100 feet or so within the building.

Firefighters, meanwhile, swarmed the building to attack the fire, which ignited in the roof above the social hall. The sight of the flames caused concern that the fire could quickly spread and get out of control.

“Once shingles get going,” Hipps said, “they burn pretty good.”

A crew made its way into the attic while the Grove City Volunteer Fire Department’s ladder truck arrived for an aerial attack.

“The hot melted shingles were dripping into the attic,” Hipps said. But within 20 minutes, the fire was contained.

“Quick action all the way around,” he added, “prevented something a lot worse from happening.

In all, about 50 firefighters from five departments assisted.

By the time crews left, all of the patients were back in their regular rooms. The room that sustained most of the damage was cordoned off, authorities said, and was to be inspected today by the state Department of Health.

The storms, meanwhile, kept firefighters in Butler County busy for much of the late afternoon and evening.

A house on Virginia Lane in Center Township that reportedly was hit by lightning about 4:35 p.m. was spared fire but sustained a blackened wall.

Almost simultaneously, lightning struck a utility pole on Sky View Drive in Buffalo Township, blowing out a transformer and setting a tree on fire.

Lightning struck at least one other utility pole, blowing out two transformers outside the Herman Volunteer Fire Department station on Herman Road in Summit Township.

Fire departments were also called out between 4:48 and 9:06 p.m. for trees blocking the following roads: East Old Route 422 and Burke Road in Clearfield Township; Thornwood Drive in Butler Township, Boyers Road in Marion Township, Mourning Dove Road in Worth Township and Goldscheitter Road in Clinton Township.

The downed trees in some cases were also blamed for pulling power lines.

West Penn Power reported that 1,300 customers in Butler County, mostly in the Saxonburg area, lost electricity during the storms.

Crews worked through the afternoon and evening, a company spokesman said, with the last few customers having their service restored by early this morning.

About 50 customers of the Central Electric Cooperative in scattered areas lost power between 4 and 6 p.m., a spokesman said. All of those customers were restored within an hour.

A telephone call to Penn Power was not immediately returned this morning.

The National Weather Service is calling for a chance of thunderstorms in the county this afternoon with high temperatures in the upper 80s. Chance of rain is 40 percent.

A slight chance of showers and thunderstorms is expected this evening. Lows are predicted in the upper 60s.

The forecast for Tuesday and Wednesday is mostly sunny during the day and clear at night.