It was funny. Peter Wilt, the first GM and more or less founder of the club was the one who pissed off Nike at the time by changing the image, logo, crest and name at the last minute. And when I say last minute, I really do mean it. The idea of The Fire had been introduced, but was turned away.....well, Peter held that it was going to be the Fire, but went along with the execs until he got to the podium at the team's grand unveiling and introduction at Navy Pier on October 8th, 1997. At the actual last minute, Peter pulled up the slides and description that match the vision he he hadand the images of the Chicago Fire as we know them were born.
Also of note, only Chicago and DC United have had their brand remain the same in visuals and uniforms--all other clubs have either re-branded or gone through major overhauls of their name and look.