Why the Migrant Crisis is a 'Mega Trend' Listen Download Embed Share Share this on Facebook (Opens in a new window) Share this on Twitter (Opens in a new window) Share this via Email Syrian refugees and migrants along a railway line as they try to cross from Serbia into Hungary near Horgos on September 1, 2015. ( ARIS MESSINIS/AFP / Getty ) Produced by PRI and WNYC