Spencer West was just starting to lather his shampoo after a grueling run in the Boston Marathon when he heard the blast.

“I had never heard a bomb in my life, but there was no mistaking it,” West, 41, who lives in Davie and practices law in Coral Gables, said Tuesday by phone. “Then, another blast. I ran out of the shower and looked out the window. We saw everything.”

For the past three years, West and his wife, Julie — both Boston Marathon racers — have reserved a room on the third floor of the Lenox Hotel that overlooks the finish line. What they saw Monday was carnage and terror punctuated in red.

“It’s really sad,’’ said Julie West, 38, who finished the marathon in 3 hours 23 minutes 21 seconds — less than an hour before the explosions. “I’m ready to go home. Crazy two days.’’

The Wests, along with their 9-year-old son, Patrick, and 6-year-old daughter, Madison, were part of a large contingent of South Florida marathoners who headed to the airport Tuesday after harrowing experiences, but thankful to have survived uninjured.

Spencer grew up just outside Boston in Somerville and has run Boston five times, including Monday, when he represented Runner’s Depot Racing Team with a speedy 2:57:37 finish. “What a nice day and beautiful weather, with everyone cheering us on,’’ he said. “Such an innocent event and an honor to be in it. I just hope this doesn’t deter people in the future.”

Patrick made his father promise he won’t run Boston next year “unless they catch the person who did it,’’ West said. “I told him, ‘They’ll catch the person.’ ”

Rob DeClercq, a triathlete from Davie and a teammate of West’s, finished his first Boston marathon in 3:10. When DeClercq had completed his run, he met his wife and fellow marathoner Jeff Boden of Coral Gables. They went in a restaurant three blocks from the finish. Then a manager announced “there was criminal activity outside’’ and no one could leave, DeClercq said.

“We were a little confused, like, ‘What the hell does criminal activity mean?’ I thought someone had a gun or got in a fight. About 10 minutes later they turned on the TVs and we found out. When we finally left, we walked three miles back to our hotel. The streets had this creepy feel . . . but everyone was calm.

“I will come back without a doubt, but emotionally it has been difficult.”

Sarah Dunsford, 20, grew up in Ponte Vedra. The student at Boston Architectural College was snapping photos during the last stretch of the marathon with her roommate and two acquaintances. One of them told the others she was going to the finish line. Dunsford and her roommate didn’t feel like dealing with the crowd.

The other two went together and were caught in the blast. One had an undisclosed leg injury; the other “shattered her ankle and had fragments of bomb within her shin,’’ said Dunsford, who visited her Monday night at Tufts Medical Center. “She went into surgery late last night. We don’t know if they were able to save her foot, but we’re praying. It’s horrible.’’

One South Floridian, who miraculously crossed the finish line about 60 seconds before the first explosion, said the experience caused her to change her attitude.

Lauren Fuchs, 52, of Coral Springs, came to the race after undergoing surgery and radiation treatments in October for breast cancer.

“I have not been very lucky in the last couple of years,’’ said Fuchs, who works for Running Wild in Fort Lauderdale and is married with two kids. “I started training again in December so I could get here, and I came to this race not really knowing if I could do it.

“I survived breast cancer, and [Monday] I started thinking, ‘Maybe my luck has changed.’ ”

Public Insight Analyst Stefania Ferro contributed to this report.