Without knowing why they went off the end, either marginal braking or landing long will probably be the outcome. Pilots who land long are usually the answer. I have landed as the first flight of the day at an airport at high altitude and in my 737 realized that when I came out of reverse at 60 knots I was going to have an overrun because of braking action nil so used reverse to stop. The brakes were useless. We had no braking action reports because we were the first flight in about 6AM and the first flight in after they closed the airport for the night.