WTC6 US Customs office?
https:// en.wikipedia.org/wiki/Six_World_Trade_Center
just started researching on this. came across this so far.
https:// steemit.com/conspiracy/@budz82/september-11-2001-what-exactly-happened-to-wtc6-on-9-11
http:// 911research.wtc7.net/wtc/attack/wtc6.html