Civility flys out the door in many bad situations. Look at New Orleans after Hurricane Katrina.
Actually I found the majority of folks to be extra civil after Katrina. Most knew they were tired and stressed. So when somebody did something "uncivil", rather than reacting in kind, most gave the offending person a lot of slack and did their best to calm the situation. Onlookers did their best to intervene and talk the arguers back to "reality".
There were strong feelings, tensions and many arguments but they quickly resolved and usually with an apology from both sides.
Of course this was not always the case, but by far, it was the most common. Still stress was very evident and only the patient understanding of those involved kept things from escalating out of control.
It was not all similes and roses, but it was not constant open hostility either. Folks did well and deserve credit for their strength and understanding.