A Mesa Airlines Canadair CRJ-900 on behalf of American Airlines, registration N943LR performing flight YV-5919/AA-5919 from Sioux Falls,SD to Phoenix,AZ (USA) with 76 people on board, was enroute at FL360 about 250nm eastnortheast of Colorado Springs,CO (USA) when the crew initiated an emergency descent . . .
Source: http://www.avherald.com/h?article=4af385ba&opt=0