Tomato leaves in containers turning brown/yellow
I planted four tomato plants in containers around May 1..they have been growing well for the past month, hearty stalks, stems and leaves. Overall May was extremely dry in MD, but we had a day of solid rain approx two weeks ago (maybe 2 inches in one day). As a result of being so dry I had been watering in early am and in the evening, the plants sit in almost full sun on a deck off the back of the house. Just after the rain episode, I noticed one plants leaves around the base of the plant start to yellow. Soon the yellow leaves began to appear all around the plant, eventually these yellow leaves turn brown, dry up and are basically dead. I have noticed the other three tom. plants start to follow this same pattern. Is this a fungus/disease...early blight? Is this overwatering? I am confused, also concerned all four will die and never produce anything??