Original sentence: Conspiracy theorists have claimed that the collapse of the World Trade Center (especially Building 7) was caused by explosives.Since well before the attacks, various conspiracy theories have emerged that question the official government and media account of that day
Edited sentence: Conspiracy theorists have claimed that the collapse of the World Trade Center (especially Building 7) was caused by  explosives.Since before the attacks various conspiracy theories have emerged that question the official government and media account of that day.There are similar conspiracy theories about the  1941 Attack on Pearl Harbor, see Day of Deceit