If it is/was a blight, you will need to ditch the soil in your Earth Box (you can use it to amend other beds though) and clean the box before planting it again. Btw, tomatoes do stop setting fruit when the temperatures get too hot, so that might have been a contributing factor. Daytime temps over 100 and/or nighttime temps over 70 or so, I think is about when mine stop setting fruit.
So, next year, start your tomatoes earlier so you'll get a good harvest before they give up in the heat.
