Even as some of the most advanced runners crossed the finish line, they recalled how the heat and humidity made it hard to breathe during much of the 13.1 mile course.
Today, race organizers tell NewsChannel 3, it wasn't dehydration or heat exhaustion that caused one man to collapse just a mile into the race.
They believe a heart attack may be to blame. They say the call came in as a cardiac situation.
It happened at mile marker one where, witnesses say, they saw the man collapse near the intersection of Pacific Avenue and 24th Street.
An off duty Beach officer who was also in the race and bystanders rushed to help.
The Virginia Beach Volunteer Rescue Squad rushed him to the hospital, but he didn't make it.
The runner has now been identified as 50-year-old Larry Wegner of Glen Allen, Va.
Medical crews working the race say it's not unusual to treat people for things like heat exhaustion and dehydration and give them ice to help minor aches and sprains.
But out of the thousands that participated Sunday, EMS officials say they took 13 to the hospital.
At this point, race organizers haven't confirmed an exact cause for the man's death.
They suspect it stemmed from an underlying issue.
Right now, EMS officials say they're going through all medical reports from that day to pinpoint which of the 13 people taken to the hospital passed away.
Sadly, this comes as the third death during this race in the last five years.