I don't see as disaster situation is more dangerous that any similar situation in every day life. If alone how do you estimate risks. As feminists very correctly point out rape is always a consideration and risk. Men alone or in groups are always something of a risk. Vulnerability and the presence of alcohol add to this risk. As do many other factors.

It has been noted that in a disaster situation, and until things regularize, many confirmed predators will tend to take fewer risks because they are out of their normal environment and comfort zone. Wind comes up, the creek rises, tornado plows through town, or a wildfire threatens and predators tend to go off their feed because the normal clues that keep them safe are mixed up. Unable to tell where super-predators are they take fewer risks. Even their normal complacent and unaware victims are stressed, hyper alert, jumpy.

After Katrina NOLA experienced a reduction of violent crime. Even the police, those few still on duty, noted that many of the neighborhood thugs were to busy helping family and friends to maintain their violent ways.

None of this suggests that predators, or opportunists, can't or won't act up and take advantage of a situation. As always you have to stay aware and trust your instincts.

I think there are no easy answers. Excessive suspicion, pushing people away who might help you, can hurt you as much as unwarranted trust. Always pays to have allies and people covering your back. Trust can be provisional. I don't trust myself unconditionally so I think it is unreasonable to see people as trustworthy or not. It is something that constantly being renegotiated as the time and situation changes.