To his credit, he does go in after fearless guy #1... Looks to me like no one was really sure if anyone would be alive in there, you can see fearless guy #1 cautiously moving around the wreck at a distance to try and spot someone at first (at least, looks like the same person). I guess once it became clear someone was moving around he ran in and the others joined.
Not everyone will run into danger, and unless you've been in a situation like that and you know what kind of person you are, don't be too quick to judge.