Kentucky plane crash: death toll rises to 12 as officials investigate how engine detached

NTSB agents arrive in Louisville to investigate what caused engine to fall off UPS cargo plane and left wing to catch fire

The death toll from the UPS cargo plane that exploded into a fireball in Louisville on Tuesday night has risen to 12, said Craig Greenberg, the city's mayor. At least 15 people were reported injured and several individuals" were still unaccounted for, Greenberg said in a social media post.

A federal investigator announced earlier Wednesday a UPS cargo plane's left wing caught fire and an engine fell off shortly after takeoff from the Louisville Muhammad Ali international airport, causing the plane to crash and explode into a fireball.