Family members and fellow bikers are keeping watch at Jackson Memorial Hospital after two bicyclists were badly injured when they were struck by a hit-and-run driver on the Rickenbacker Causeway Wednesday morning, Miami Police said.
Police said late Wednesday they are questioning a person of interest in the case.
The incident happened shortly before 6 a.m. on the eastbound side of the causeway near the William Powell Bridge, as a group of bikers was heading to Key Biscayne.
Both of the injured cyclists were rushed to the hospital, including Aaron Cohen, an experienced biker, Ironman competitor and marathoner, who police said is in critical condition and may not survive.
"The main problem is a massive head injury," said his wife, Patti Cohen.
The other cyclist sustained a broken leg and will be okay, police said. Enda Walsh said he heard a loud bang, "and the next thing I know I was on the ground."
"Aaron was 30 feet up the road, lying on his back, not moving," he said.
All of the bikers were wearing helmets when the crash happened, they said.
"There are wide lanes going in either direction and there is a huge bike lane, so there is no excuse for a cyclist to get hit," said Mickey Witt of BikeSafe, a Miami-based biker advocacy group.
The car, described as a silver 2009-2011 Honda with possible damage to the right side of its hood, fled the scene. Police did not have a description for the driver.
"That someone would do this and just drive away, I just can't imagine," Patti Cohen said.
NBC Miami's Amara Sohn contributed reporting.