Lauren Fuchs had just finished running the Boston Marathon Monday and was half a block away from the finish line when she heard the thunderous booms.
"It was the loudest thing I've ever heard. I’ve never heard anything like that,” the Fort Lauderdale resident recounted. “Someone said, maybe they planned that, maybe it was like a celebration thing. But all you saw was black smoke, and that's not a celebration."
Panic set in, and people around her immediately thought they were under attack, said Fuchs, who had run her third marathon in Boston.
"Just seeing people's expressions on their faces, it was almost like duplicate expressions from 9/11,” she said.
The two explosions near the finish line Monday afternoon killed three people and injured more than 100, authorities said.
Fuchs underwent more panicked moments as she tried to find her husband in a sea of people. Five minutes later, he saw her, they hugged, and they left the area.
Part of South Florida father Jose Aponte’s afternoon was filled with suspense and angst after the blasts in Boston. His son, Nick Aponte, is a college music student there.
Dramatic Photos: Boston Marathon Blasts
Nick Aponte knew his parents would worry, so he called his mother.
"He called her to let her know that he was OK, that nothing happened to him, but he witnessed everything,” his father said.
Nick Aponte, who didn’t have class Monday, was getting lunch with his friends when chaos erupted a short distance away.
"I was confused. I thought it was part of the event, but then the second one (went off) not quite 5 seconds later,” he said of the blasts.
AUDIO: Listen as a Boston Marathon runner gives details of the aftermath.
He said people were running everywhere, and many of them were crying.
“It was crazy, really horrifying,” he said.
Nick Aponte said he tried calling friends to make sure they were OK, but he couldn’t get through on his cell phone. But eventually he learned that all of his friends were accounted for.
In South Florida, Aponte’s parents were also resting a little easier Monday night – though his father urged him to take precautions.
"I text (messaged) him and told him to avoid crowded areas and to go home,” Jose Aponte said.
NBC 6's in-depth coverage of the Boston Marathon Explosions
Photo Credit: NBC 6 South Florida