Answer:
The terrorist attack on the Twin Towers
Explanation:
This question refers to the reaction that Aaron Brown, a news anchor, had upon witnessing the attack on the Twin Towers on September 11, 2001. Brown was a witness that day, as he had been standing on a roof in New York City about 30 blocks from the World Trade Center. Brown described "a huge explosion" and a "mushroom cloud" of "billowing smoke." However, Brown also reported that he did not think the towers were going to collapse.
