Denver nears its breaking point as migrants and the cold pile in

​ This is what an overwhelmed city can look like: a preschooler sleeping under a bridge for a month; crowds lining up each night to get food and shelter; and the mayor calling out for help. And when that city is Denver in the winter, and the overnight temperatures sink below zero degrees Fahrenheit, the problems are life-threatening. Read More Breaking News, Latest News and Videos | CNN