The man, who was employed as a private contractor to wash the windows at the building on 17742 Beach Blvd,. was using a 30- to 40-foot extension pole with a brush at the end, Lopez said.
"It looks as if he was maneuvering landscaping on the building," Lopez said. "While maneuvering the extension pole, he brought it in contact with the power line, and that immediately electrocuted him and killed him."
The power line was charged with 12,000 volts, Lopez said.
The accident is being investigated by the Occupational Safety and Health Administration and the Huntington Beach Police Department.
Some amateur footage of the incident was caught by witnesses, Lopez said.
Edison shut down power in the building and surrounding businesses to safely remove the pole and the body from the scene, he said. The power was restored a few hours later.
It's not clear whether the man made a reckless mistake that resulted in the accident, Lopez said.
"People use tools like that all the time," he said. "Around power lines, you just have to be cautious."