John Twitty was supposed to meet his family at the finish line of the Boston Marathon on Monday.

The 55-year-old Andalusia runner had finished the race and was walking toward the line to get goodies when he heard an explosion behind him.

“All I could see was a white plume of smoke,” he said.

A few moments later, he and other runners heard another blast.

“Basically, we were told to keep moving,” he said.

He soon learned by text that his wife and three children were lost and delayed. It was a great message, he said, to know they were OK.

Two people died and at least 141 were treated for injuries sustained from explosions near the finish of the storied Boston Marathon. At least 17 of the injured were reported in critical condition. Federal authorities classified the bombings as a terrorist attack, and at least one and possible two other explosive devices were found.

While the Twitty family was delayed downtown while rescue workers dealt with the aftermath of the bombing, he said Monday night they didn’t really see the chaos until they returned to their hotel room hours later.

When he heard the bombs, he said he immediately knew something terrible had happened.

“In my mind, I wondered, ‘What’s next?’ ” he said.

Twitty finished the 26.1 mile race in 4 hours and 19 minutes. It was his first time to run Boston, but he doesn’t plan to return.

“Not just because of what happened today,” he said. “It’s just and expensive venture.”

He qualified to run this year’s marathon when finished Huntsville’s Rocket City Marathon in 3 hours and 37 minutes. Two months ago, he ran the Mercedes Marathon in Birmingham and qualified for Boston for next year. While he’s not planning to return, he has until September to change his mind.

“The race is age graded, so it’s not like I’m running with the Kenyans,” he said. “

The Boston Marathon, begun in 1897, is the world’s oldest annual marathon. The event attracts 500,000 spectators each year and an average of 20,000 runners each year, making it New England’s most widely viewed sporting event.

Lelisa Desisa of Ethiopia won the men’s race yesterday, finishing in 2 hours, 10 minutes, 22 seconds. Kenya’s Rita Jeptoo won the women’s race for her second Boston victory, finishing in 2:26:25.