Hello Erin, and thank you for contacting us at the UVM Extension Master Gardener Program with your question.

I am sorry that you are seeing these issues with your tomatoes.   Thank you for sharing the photos, as they make a huge difference in helping to figure out what might be going on.   

The images do suggest that it could be late blight, which of course you'd want to address as soon as possible, especially in a caterpillar tunnel.    A question first though:  are these affected leaves from the top, bottom, or various locations on that plant?

I include below a few articles about identifying late blight and how to address it.  They all include either photos or planting condition details to help you determine whether it is late blight or perhaps a less devastating mold. 

https://content.ces.ncsu.edu/tomato-late-blight

https://www.uvm.edu/sites/default/files/Tomato-Problems.pdf

https://www.uvm.edu/sites/default/files/Extension-Master-Gardener/lbfaq_001.pdf

Please feel free to follow up here with information about the location of those leaves you removed and any additional questions.

I hope you are able to keep your tomato beds flourishing for a while yet!

Thanks for your note,

Michelle

Hello Erin, and thanks for the additional photo.

That location on the plant, plus the fact that it is on the end of the tunnel suggests that it could be late blight, with the pathogen spores being blown in during any of the recent storms.  (Do you know of any neighbors with gardens who have late blight this year?)

As you saw in the literature we shared, typically the suggestion would be to remove the leaves and possibly the affected plant, though perhaps you can keep an eye out (over the next 3-5 days) and remove any additional affected leaves and pull that plant only if necessary.

I wish you luck with the tomato harvest!