NBC L.A. helicopter's final broadcast could hold key clue to deadly crash

On Wednesday, investigators examine the site of the NBC4 news helicopter crash in Chatsworth. (Kayla Bartkowski / Los Angeles Times)It was a night of devastation in Chatsworth that began with a deadly Metro bus collision and ended with the fiery crash of an NBC4 helicopterthat left two journalists and, on the ground, a bystander dead.Tuesday’s scene was a mixture of confusion and chaos, with first responders fanned out across two catastrophes and television news teams desperately tryi