CHARLESTON, W.Va. -- After the June 29 "super derecho," a record 573,000 Appalachian Power customers in West Virginia and Virginia were without electricity. Relentless heat made the blackout miserable, and potentially dangerous. Surrounding areas were in the same difficulties.

All of those factors made this storm's damage the worst on record for Appalachian Power, Charles Patton, company president and chief operating officer, wrote in a letter to leaders around the region.

More than 4 million homes and businesses in 10 states lost electricity because of the straight-line windstorm that moved about 70 miles an hour, dropping little rain but bringing hurricane-force winds. That included 330,000 Appalachian Power customers in West Virginia.

With a hurricane or large winter storm, Apco generally has warning time to alert extra repair crews, who begin driving in to the region in advance. But in this case, the warning time was short. Crews in surrounding areas were working on their own repairs.

So Appalachian called in help from 22 states, some as far away as Texas and South Dakota. Nearly 5,200 workers toiled in blistering, debilitating heat, some in 30-minute rotations on and off. They repaired more than 90 distribution substations, more than 100 transmission lines and more than 1,500 utility poles. Even while they worked, more storms on July 1, 3, 5 and 8 added 105,000 new outages to the list.

Hotels filled up, so after their 16-hour shifts, workers bedded down at West Virginia State, Marshall and Concord universities, the University of Charleston and Brushfork, Welch and Eleanor National Guard armories.

In his letter thanking customers for their patience and support, Patton wrote that 95 percent of customers were restored to service within nine days. All power in West Virginia was restored by July 15.

 Patton says he welcomes reviews of the storm response that are sure to follow. Even before the storm, the reliability of West Virginia's electrical service was a topic for the state Public Service Commission. Power outages in West Virginia take almost four times longer to fix than the national average, according to the U.S. Department of Energy. While some of the difference might be blamed on terrain, steep slopes and ice-covered trees, that don't explain it all. Upstate New York, for example, with similar terrain to West Virginia, does not have such long outages.

The PSC was already considering rules to set reliability targets for electrical systems like most other states have. Two weeks before the now-infamous derecho, a PSC staffer warned that plans proposed by the industry would do little to improve the reliability of electricity in the state. Those plans would simply require companies to complete work that had been neglected for 10 years.

West Virginia residents cheered repair crews when they rolled into neighborhoods. Residents offered them cold drinks and warm welcomes, as they should.

"Yes, customers were frustrated, hot and tired of having no electricity," Patton wrote. "But by far most people recognized and were supportive of the work we were doing and had nothing but kind words for our crews."

As both residents and Appalachian Power continue to think about this experience, there will doubtlessly be plenty of lessons to apply before the next one.