Tomato anthracnose is a serious disease of processing tomatoes caused by the fungus Colletotrichum coccodes.
How to spot it before its too late...
There are ways of spotting this in your tomato plants. Early symptoms appear on ripe fruit as small, slightly sunken, water soaked circular spots. The lesions increase in size, become more depressed, and the central portion darkens. The darkened area contains many small, dark, fungal structures from which masses of salmon-colored spores are released in moist weather. As the fungus spreads within the fruit, a semi soft decay occurs. anthracnose is more prevalent on poorly drained soils, tomatoes should be planted on well-drained land. Several fungicides are registered for use on tomatoes to control anthracnose.
http://vegetablemdonline.ppath.cornell.edu/factsheets/Tomato_Anth.htm