This piece is one of a series that looks at the Knight News Challenge winners, and their thoughts on future trends, on the occasion of the challenge’s 10th anniversary. There is no other way to say it: Growth at Crisis Text Line – an emergency service for people at wit’s end – is, sadly, explosive.In October, the four-year-old service crossed a major milestone when it processed its 50 millionth text message. That is the number 50, followed by six zeroes.If that doesn’t really capture the organization’s progress, try this number on for impact:“If you look at our growth trajectory,” says founder Nancy Lublin, “it’s going to take us nine months to do the next 50 million. We’re growing really fast.”She says there are two main reasons why Crisis Text Line, which won a 2014 Knight News Challenge and has received subsequent funding from the foundation, is seeing its numbers skyrocket.