Well they certainly seem to have some kind of problem, maybe insect infestation or infection of some sort - however, the browning may be due to insufficient water at the root. I'm puzzled regarding the size of the trees if you only planted a week ago- were they potted ones? and if so, did you keep them in the pots for ages?

There could be a number of factors at play here, the main one being transplant shock. The trees are susceptible to other problems at this time. The ideal time to plant is Fall or early Spring. Keep the trees irrigated continuously until they go dormant in the Fall. They should be OK once they emerge from dormancy in the Spring.

They look like large boxed or balled and burlapped ones. Common enough in the U.S., when people don't want to wait for their trees to grow. It takes massive amounts of water to start, though, especially the latter method. The second picture looks like a leaf spot disease, while the third picture looks like drought damage. Premature coloring on maples is usually caused by drought, too.

If I get them plenty of water now, will they come out of it? Or did I kill my trees?

They arent' dead. Yes, keep them watered. Let them naturally go into dormancy (that's what will save them). In the Spring, it should bud and leaf out. Don't expect it to do much now in September.