it appears the nearest 3 of the plants have a similiar concave burn effect? I do not mean this time, it appears they have had this burn before? Is there some shade offered further down the drive such that the convex natural shapes are impeded by solar burn? Not enough credit is given to water for its property of absorbing IR wavelengths and evaporating that same heat in a highly emissive form factor..
Two of my Green Giant Arborvitae had the same browning. I cut the branches off at the trunk and immediately burned them. Not knowing what the problem was I bathed the tree in Sevin spray. I pulled all the mulch away from the base and burned that. I put fresh commercial mulch down and sprayed the tree and ground with a fungicide that I had. This was a desperation move since I didn’t want anything to happen to my bonsai conifers. As of yesterday the two trees look fine with no evidence of browning at all.
Yep, I see many bagworm cocoons in your last picture. There is nothing you can do now. Back a few months ago you could have sprayed. You can remove the dead limbs as @Silentrunning did but your trees will probably be lopsided. Since you know that bagworms are present or can be present in great numbers you might think about replacing the tree with something that bagworms don't like.