They are trying to escape the chlorine fumes coming off the water....was it an especially hot sunny day? The Sun and warmer temps make chlorine evaporate faster than normal and it sounds to me like they didn't like it much...I've not grown any around a pool, but just from observing plants around mine, some plants are very sensitive to the chlorine fumes and some it doesn't bother at all. Try moving them further away from the pool and see what happens.