The announcement that the triathlon races would proceed as planned, with the Seine deemed clean enough for swimming, drew thousands of Paris spectators early Wednesday morning.The triathlon is one of the few events at the Paris Olympics, or at any Olympics, where the public can go and get a free peek without having to have a ticket.Thousands of people crowded the banks of the River Seine to watch an Olympic sport, especially considering the high cost or unavailability of tickets for many other events.