The story I was told from Sox historian Rich Lindberg and others is that when Bill Veeck sold the team to the current group, he felt that since he was the owner all material of that nature regarding the White Sox (i.e. old footage, highlights etc.) belonged to him and he took them.
When I spoke with Mike Veeck, he denied that accusation.
Bob Grim, the Sox director of broadcast operations has told me that the Sox never had much material before the late 70's and neither does MLB. Rich King from WGN-TV told me they don't have much on the Sox before 1983 in the station 'morgue.'
What is a fact is that according to a story in TV Guide from the mid 80's examining the question of why MLB doesn't have historical material for a lot of events was that many stations tossed out all the film they had as they were going to "electronic news gathering" (VHS) equipment in the mid 70's.
WGN-TV was specifically cited as throwing out all of the thousands of reels of film they had shot on the Sox and Cubs in the 1950's when they moved to their new location in 1962. They quoted the former news director as saying that all that film was tossed out into an alley.
Like a previous poster said, back in the day, nobody knew that this stuff would be valuable and at the time it was simply to expensive to build climate controlled warehouses to store all this film.
Unless it is contained in almost perfect conditions it will not last more than five to 10 years, it will simply break down and fall apart.
Sad but true.
Have never heard anything about a fire at Channel 44 destroying material. I also know and Hal Vickery, (Fallin Arches) can confirm this that Nancy Faust does have some material including the TV video of Dick Allen ruining Nolan Ryan's no hit bid in the 9th inning of a game and winning it with a hit.