Artillery, rockets and bullets don't give a shit if you're a Delta Force SEAL Ranger who's gotten millions of dollars of training time and the best fucking gear in the universe. The only reason special forces operators have gotten a reputation for being unkillable and nearly always coming home from a mission is because for the past 30 years they've been operating with gear that the dudes on the other side have either never heard of, or couldn't dream of having in their wildest fantasies, with 24/7 CAS and evac available for them at a moment's notice, with constant intel being piped to them from air assets stationed above their AO with FLIR and all sorts of other crap.
And even then you get entire squads of spec ops guys getting schwacked in Africa (forget the country it happened in), Blackhawks going down in Mogadishu, SEALs getting obliterated by a $30 RPG-7 round because their helo was just hovering out in the open.