Bag Worm Damage
Bagworms eat needles. They leave areas of a tree dead, but not bare. See the photos here: https://extension.umd.edu/hgic/topics/bagworms-trees-and-shrubs Look a more images onlline.
The lower bags on these trees haven't done much damage this year, but each one may contain hundred of eggs that will hatch out next spring. Remove and drop in a bucket of soapy water--do not drop on the ground, where they will survive.
We can't tell if the brown area is from bagworms or something else. Perhaps you can see with binoculars. Read through the link above for strategies to handle bagworms.