On 27 June, authorities discovered an abandoned tractor-trailer outside of San Antonio, Texas, filled with dead people smuggled from Mexico and Central America. Fifty-three migrants would ultimately die in the tragedy.
It was the worst such incident in US history, and a sign of how things have changed at the US border in recent years: cross-border human smuggling has gone from a fragmented business of small-time criminals to a $13bn-a-year enterprise controlled by organised crime, according to the Department of Homeland Security.
