MARATHON (CBSMiami) – For the first time in the history of the 7-Mile Bridge Run marathon, runners at the starting line were told it was too dangerous for them on the bridge, and the race was canceled. It’s not known if, or when, it will be rescheduled.

Runners had lined up before dawn to take part in the race, which should have heard the starters gun at about 7:30 a.m. Saturday. However, as start time approached, dangerous lightning and heavy rainfall caused organizers of the 31st annual to stop the runners and cancel the race.

About 1500 runners from all over the nation had registered, and parts of the Overseas Highway through the Keys were set to be closed temporarily for the runners’ safety.

Despite the weather, the highway was re-opened as it was judged safe for vehicle traffic

The Marathon Runners Club’s Seven Mile Bridge Run began as a dedication run in 1982, celebrating the opening of the “new” Seven Mile Bridge. It is the only known run that is completely surrounded by water from start to finish.

The marathon’s field of 1,500 runners was filled within six minutes after online registration opened at 6 a.m. February 23.

Paul Marmaro, a fitness instructor from Delray Beach, has won the race eight times and continues to hold the course record of 32 minutes and 59 seconds set in 1998 and was registered for the race.

So is Jason Bodnar, a North Carolina dentist who has won five times despite dealing with a phobia of crossing bridges.