I just found this interview with the operator of a freight elevator who was at work when WTC 1 was hit. It is relevant to the Rodriguez story - Rodriguez was in the basement and helped a colleague who was burned there when there was an "explosion" from a freight elevator shaft following the impact.
http://www.usatoday.com/life/sept11/2002-09-10-surivivor-griffiths_x.htm"Arturo was running 50A, the big freight car going from the six-level basement to the 108th floor. When American Airlines Flight 11 struck at 8:46 a.m., Arturo and a co-worker were heading from the second-level basement to the 49th floor.
"Arturo heard a sudden whistling sound and the impact. Cables were severed and Arturo's car plunged into free fall.
"The only thing I remember saying was 'Oh, God, Oh, God, I'm going to die,' " he says, recalling how he tried to protect his head as the car plummeted.
"The emergency brakes caught after 15 or 16 floors. The imploding elevator door crushed Arturo's right knee and broke the tibia below it. His passenger escaped injury."
I think that this shows that something nasty was heading down a lift shaft that went from the impact floors to the basement floor where the janitor was burned. It certainly appears to be fuel spilled from the plane.
His wife was also an elevator operator and escaped from the 78th floor that day. She said:
"All that morning, Carmen had been carrying hundreds of passengers from the 78th-floor sky lobby to the bond-trading offices of Cantor Fitzgerald on the 101st to 105th floors and the Windows on the World restaurant above that.
"A full elevator had just left the 78th floor, and Carmen was about to carry up six or seven stragglers. The plane struck as the doors of her elevator closed. They could hear debris smash into the top of the car; then the elevator cracked open, and flames poured in. Carmen jammed her fingers between the closed doors, pulled them partly open and held them as passengers clambered over and under her 5-foot-6 frame to escape.
"Before finally throwing herself out onto the lobby floor, she glanced back to be sure the elevator was empty. That was when fire scorched her face with second- and third-degree burns, and literally welded her hooped right earring to her neck. Her hands were badly burned.
"Carmen was helped down the 78 floors to an ambulance just as her husband was carried out of the basement on a piece of plywood and a hand truck, each certain — after seeing the burning buildings from the street outside — that the other was dead."
I think this shows that fuel and debris affected both passenger and freight elevator shafts following the original impact.