The movie was entertaining, but became frustratingly unrealistic in the last half hour. I won't tell you exactly what happened but I was yelling why don't they do this or that, or you have got to be kidding me for almost the entire last half hour. Especially the ending where the victims are located in a place where there was no chance they could have had access to, but they are still spotted immediately by their rescuers. I believe you should suspend disbelief to a point when watching a movie, but the movie makers also have a responsibility to keep things within the realm of possibility.
I am a professional firefighter so I understand that in a crisis a lot of people do stupid things and use bad tactics when facing life threatening challenges. But to me it would be more entertaining to see people who are using good judgment and not freaking out.