A documentary about the collision at Tenerife seems to imply that the Pan Am flight attendants left the aircraft without helping a single passenger? Is this correct? If so how is this possible? Are flight attendants required by regulation to place their own lives at risk to save passengers?
In training, flight attendants are given lots of emergency training, but always with the caveat that they are under no obligation to put themselves in danger. Emergency procedures should proceed up until the time a flight attendant feels they are in danger, then they are to evacuate the airplane themselves as quickly as possible.
There was a long standing joke among flight attendants when I was working, which was the most important emergency instruction you can give: Follow me! Funny, but not really. It keeps things in perspective. Not commonly known is that any emergency responder today operates under the same conditions. You are not being paid to put yourself in danger beyond what your training will accommodate.
There are actually very few regulations in this regard, all of which are in 14 CFR 121.381 through 397.
Of those, only two pertain to the duties of a flight attendant. Most of the regulations are just about basic duties during planing/deplaning, but 121.397 is about emergencies:
§ 121.397 Emergency and emergency evacuation duties.
(a) Each certificate holder shall, for each type and model of airplane, assigned to each category of required crewmember, as appropriate, the necessary functions to be performed in an emergency or a situation requiring emergency evacuation. The certificate holder shall show those functions are realistic, can be practically accomplished, and will meet any reasonably anticipated emergency including the possible incapacitation of individual crewmembers or their inability to reach the passenger cabin because of shifting cargo in combination cargo-passenger airplanes.
(b) The certificate holder shall describe in its manual the functions of each category of required crewmembers under paragraph (a) of this section.
The specific part is (b), which basically means that the airline needs to develop SOP's (standard operating procedures/policies) and submit them to the FAA for approval. While this may be somewhat of a standard across operators, it is up to the airline itself to determine the extent that crew members are required to assist in an emergency.