Two American Airlines jets have mishaps at Dallas/Fort Worth International Airport

[Hatu]

One American Airlines jet slipped off a Dallas/Fort Worth International Airport taxiway Monday morning, while another AA plane clipped a concrete column at Terminal D.

http://aviationblog.dallasnews.com/2014/03/two-american-airlines-jets-have-mishaps-at-dallasfort-worth-international-airport.html/

 

[DallasConehead]

Just from the outside viewpoint, sounds like wing walkers and taxing on ice could be factors in each of the incidents?