The clock ticks down to the beginning of the 35th annual Gate River Run.
The top-seeded women take off first, given a 7-minute head start over the men. Whoever crosses the finish line first will receive a $5,000 "equalizer bonus."
A total of 18,432 runners registered for the event. It took more than 15 minutes for all of them to get across the start line.
The race is Jacksonville's largest participation sporting event, drawing people of all ages with all levels of running ability.
At all points along the 9.2-mile course, people cheer on the runners.
The elite women come off the Main Street Bridge.
Minutes after the elite runners pass, the Main Street Bridge is filled will runners.
The next time we see the elite women -- at the half-way mark as the course turns off Hendricks Avenue -- Molly Huddle, who holds the American 5,000-meter record, has a narrow lead.
About 90 seconds later, Mo Trafeh, last year's River Run champion, passes one of the other elite women at the turn.
Slowly, the non-elite runners begin to pass the half-way point in the race.
Holly Huddle, in her first River Run appearance, is cheered on as she approaches the Hart Bridge ramp.
Mo Trafeh is not far behind as he turns onto the entrance ramp to what the runners call "The Green Monster."
Many of the team and recreational runners are still going strong 30 minutes into the race.
The field of recreational runners stretches out by the 6-mile mark on Atlantic Boulevard.
For only the second time since women were given the "equalizer" start, a female crosses the finish line first. Kenyan-born Janet Cherobon, who began an American citizen just six months ago, enjoys her first-place win.
Molly Huddle crosss the 15K finish line second. Not bad for her first River Run appearance.
Mo Trafeh sprints to his third River Run 15K men's championship. While he finishes behind the two women and about one minute off the American record time, he still pockets the $12,000 first prize.
"I just wanted to go out quite a bit faster to know that we're ahead of the guys," Cherbon told Channel 4's Sam Kouvaris. "I think it worked out well."
"I gave my best and came up short catching Janet," Trafeh said. "The last 5K was really tough. The last hill -- it was really windy -- it was really hard to make up that time."
For the next 90 minutes, thousands of recreational runners achieved their goal by finishing the 15K.
For many, the run was mostly about having fun. But even superheroes want to know their finish time.