Long-time runner Nancy Corsaro had completed her 13th Boston Marathon and was trying to get out of Prudential Building garage when she heard two "loud bangs."
The sounds Corsaro heard were from reported explosions near the finish line after 3 p.m.
The long-time Methuen resident, who finished in 3:27, was in a car with her husband, Frank, her dad, Dick Munroe, her son, Michael Corsaro, and brother, Don Munroe.
"My dad said, 'That doesn't sound like a plane hitting buildings,'" said Corsaro, 52. "My husband said it sounded like a bang you hear from the back of garbage truck. The next thing we knew, people were running by us with panic in their faces. We knew it was something bad."
Corsaro said they couldn't get out of Boston on Storrow Drive so they headed out on Route 9 to Route 128.
"Cop cars were flying by us as we were on Route 9," said Cosaro.