Loretta Krouk was long retired from her job as a legal secretary. But the 71-year-old Silver Spring woman stayed busy, volunteering at the Schweinhaut Senior Center and visiting Kramerbooks in Dupont Circle. An avid reader, she especially enjoyed mysteries and Russian history novels.

Krouk was killed Friday night when a maple tree crashed into her Grant Avenue home, authorities said.

She was one of five people in the Washington region killed as the powerful storm swept through, toppling trees and downing power lines.

“It’s hard,” Daniel Krouk, 44, said of his mother’s death. “I’m sure you can imagine, I don’t really know what to say about that.”

Krouk said his mother was a longtime D.C.-area resident who had worked at the now-defunct Cheshire Cat children’s book store in Chevy Chase and as a legal secretary at the Steptoe and Johnson law firm before retiring nearly a decade ago. She had two children — Daniel and his sister, Marna Young, 41 — and recently had welcomed a grandchild.

Khiet Nguyen, 27, of Burke, was killed when a tree fell on his car as he drove in Fairfax County, authorities said. Ruth W. Choffrey, 90, died when a tree crashed into her West Springfield-area house. And Mohammad Ghafoorian, 67, of D.C. was electrocuted by a fallen power line.

In Anne Arundel County, Kevin O’Brien, 25, was out for a drive with friends when a tree fell on his sport-utility vehicle, according to authorities and his father. O’Brien, who worked as BB&T bank teller supervisor, was killed. His companions, a 27-year-old man and 16-year-old boy, were injured, according to authorities.

“They were just out riding, and that storm had no warnings,” said Keith O’Brien, Kevin O’Brien’s father. “Kevin never even knew what hit him.”

Kevin O’Brien graduated from South River High School in Anne Arundel County and had completed some coursework at Anne Arundel Community College before going to work for BB&T, his father said. The 25-year-old was close to his sister, Hannah O’Brien, 16, and had recently shed 160 pounds training for a marathon. He enjoyed driving, and he often took the route where he was killed because he liked the way the trees looked hanging over the roadway, his father said.

“It was devastating,” Keith O’Brien said. “He was just a wonderful, wonderful kid. You couldn’t ask to have a better son.”

Magda Jean-Louis contributed to this report.