My three broccoli plants were fine and healthy since going into the ground May 30th. Suddenly last week or so, one of the plants appeared to have been mauled- possibly by deer. They had always been safe from critters, but to be safer, I made fencing for that raised bed. Ever since that day, however, the plant continued to lose its leaves. Then the plant next to it started to do the same. My one remaining plant is probably next. I am now wondering if an animal did this at all. Could there be some disease or bug? The leaves are strong and healthy but end up lying on the ground as if broken off. The picture shows the plants the day after the first plant was affected. Things are worse now.