Pretty sure Bin Laden was not involved in the 1993 attack.
It's actually unclear to this day how much he was, especially considering that the US government had very little knowledge of him (let alone, al-Qaeda) at the time. To the extent that he was known to US officials in the mid-90s, it was as a "financier" of terrorism, a designation which both a) misunderstood the al-Qaeda organization and bin Laden's central leadership within it and b) was based on the flawed notion that bin Laden was personally financing international terrorism with his family fortune rather than organizing and approving terrorist plots himself with the financial backing of
other donors (primarily based in the Gulf countries of course). Remember, Osama's access to his slice of the family inheritance had been frozen by the Saudi government sometime in the early 90s because of his persistent public condemnations of the royal family.
We do know that some of the people who were involved in the WTC bombing trained at camps run by bin Laden and/or his associates, and that the Blind Sheikh Omar Rahman was a close bin Laden ally. Also, Ramzi Yousef's uncle was none other than Khalid Sheikh Mohammed, the operational mastermind of the 9/11 plot - although it should be noted that KSM never actually pledged allegiance to bin Laden, maintaining his independence...
