A Bainbridge Island runner who raced in this year’s Boston Marathon said the event will be forever changed by the bombing attack Monday that left two people dead and more than 20 injured.

Peter Vosshall, 42, of Bainbridge had finished competing in his fifth straight Boston Marathon and had already made it back to his hotel, Taj Boston, about a half mile away when the explosions went off.

Vosshall said he was taking a shower and didn’t hear the blasts. His mother, who was visiting from Vermont to cheer him on in the race, did.

“She figured it was a generator or furnace exploding,” he said.

Vosshall said the explosions turned the city’s premier springtime event into a tragedy.

“I’m just sick to my stomach about it,” he said.

“This is a such a celebration for the city of Boston,” Vosshall said. “There’s a half million people on the course, cheering on the runners. It’s supposed to be a great day. It turned into a devastating situation in an instant.”

Vosshall estimated he finished the race about an hour or so before the explosions.

He said he has thought in the hours since what might have happened if the explosions happened earlier, or in a different spot along the course.

“If whoever did this was more organized or sinister, they could have set those devices up at the starting line, where there were much denser groups of people,” he said.

“There were 9,000 people standing for at least 20, 30 minutes, waiting for the race to start.”

Vosshall said his wife called as soon as she heard the news, and he posted a message on Facebook and sent emails to let others know he was OK. It’s been impossible to send a text message since, he said.

Shelly Vosshall, Peter’s wife, stayed on Bainbridge Island when Peter left Friday to go to Boston.

She had one word to describe the tragedy: “Horrifying.”

Though she figured her husband was OK because he had already finished the race, she took great comfort in hearing he was safe directly from her husband.

“Relieved. Hugely, hugely relieved,” she said.

Vosshall works as a distinguished engineer at Amazon.com.  He was one of at least seven Bainbridge runners in this year’s Boston Marathon.

This year’s Boston Marathon was the 11th marathon that Vosshall has competed in, and he usually runs about two marathons a year.

“I’m sure this race will be very, very different in the future,” he said. “I imagine it’s going to have a very different complexion.”

Other Bainbridge runners in the race include Luis Borges, 51; David McVay, 45; Ken Pinchiff, 49; Bob Powers, 50; Claudia Powers, 45; Charlie Quinn, 45 and Ron Copstead, 61.

Brenda McVay, the wife of David McVay, said her husband had finished the race by the time the explosions went off,  estimated at 2:45 p.m. Boston time.

“He was getting something to eat when it happened,” she said.

“He’s fine,” she said. “And he’s only a block from the finish line in his hotel room. He said there was a lot of emergency vehicles around and everybody is doing the best they can.”

Review reporter Richard D. Oxley contributed to this report.