tonight. >> reporter: new images tonight show the focus of the ntsb's investigation, the gaping hole where a sealed and plugged door hole blew out in a violent explosion, as the brand new alaska airlines plane was flying at 16,000 feet on its way from portland to ontario, california. the pilots wearing oxygen masks, forced to make an emergency landing. >> there was a big boom or a mini explosion in the rear of the plane. >> reporter: today passengers described a terrifying flight. >> moisture and fluid, almost like a cloud rushing from the front of the plane to the back of the plane, blew my hat back. folks in front of me, their hair was blown back. >> reporter: evan granger sitting several rows in front of the hole. >> i didn't want to look back to see what was happening. i knew something happened, and my focus in that moment was just