A chlorine spill is keeping swimmers from cooling off in one Rockland lake. Officials say a lifeguard at Lake Nanuet Park in Clarkstown noticed a chlorine leak Friday. Hazmat crews were called in and more than 60 children from a Little League Baseball camp were ordered to leave. As a precautionary measure, the lifeguard who found the leak was taken to Nyack Hospital for evaluation. The lake will remain closed throughout the weekend, but the park will be open.