Below: a farewell letter written by Carl to his wife and three children whilst trapped. Luckily the note wasn't needed, and after five hours in the smoke-filled elevator he escaped.
Interestingly Ramzi Yousef's uncle, Khalid Sheikh Mohammed, is currently being held at Guantanamo Bay and is awaiting military trial for his involvement in the September 11 attacks. He is thought to have been the plot's "chief architect."
Transcript follows. Image courtesy of MPR.

Image: MPR
Transcript
To my family — from Dad.
12:40 pm, smoky elevator 66, 2/26/93
A few thoughts if I am fated to leave you now —
I love you very much. Be good people. Do wonderful things in your life.
Barbara — I’ve always loved you, and showed you as much as I could.
Debbie — My beautiful girl, with wonderful bear hugs & kisses. Do good.
Jeff — What a terrific person, stay well, make good decisions, help people.
Doug — My boy. Discover secrets to cure lots of the world's problems.
I'm so proud of my children — they're each so wonderful.
Things I love & cherish — ideas, people, Cooper Union (Alumnus of the Year!!!), my work, my family, doing the best I could. Nothing more to say.
Love,
Dad
(Carl Selinger)
(12:59 Very smoky)
[Address; redacted]