The 1993 world trade center bombing was a disappointment because it killed six people and injured 1,000. It was the first terrorist attack on the world trade center. But the disappointment led to a man that predicted 9-11 called Rick Rescorla, he upped the security and had air vents in the stairs if there was smoke. Rick predicted 9-11 because he know that the terrorists will come back because they tried to explode the support pillars, Rick said, it won't be from land it could be by air.
9-11 was another disappointment that happen, there were 2,996 deaths and many injured. Rick know the buildings inside out