Authorities found 46 migrants dead inside a tractor-trailer on Monday in San Antonio, Texas, the city's fire department said, in what appears to be one of the most deadly recent incidents of human smuggling along the US-Mexico border. The San Antonio Fire Department said 16 other people found inside the trailer were transported to the hospital for heat stroke and exhaustion, including four minors. Officials also said three people were in custody following the incident.The truck was found next to railroad tracks in a remote area on the city's southern outskirts.