On December 20, 2008, Continental Airlines flight 1404, a Boeing 737-500, departed the left side of runway 34R at Denver International Airport, Denver, Colorado, while attempting to take off, resulting in 6 serious and 41 minor injuries. To investigate the Continental flight 1404 takeoff accident, it was necessary to determine the winds acting on the aircraft during the takeoff run. Determining winds in the air can be done readily with long established techniques, but these techniques are not suitable on the ground due to ground reactions. This paper will discuss the techniques for estimating wind on the ground and their application to the Continental flight 1404 investigation. The broader results from the Continental flight 1404 investigation and the lessons learned for enhanced aviation safety will be discussed.