The first on-archive complete tower collapse shown on TV is that of WTC2 [South Tower], at around 9.58 am EST, and this was broadcast "live" "as it happened" on NBC :
Here is gif file of that complete collapse shown on NBC that morning in "real time", courtesy of Simon Shack, www.septemberclues.info :
nbc wtc2 collapse 9: 58 am
WTC1 -CNN gif from: http://septemberclues.info/images/WTC1CNNcollapse2.gif
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