Sure does make you wonder, doesn't it? I read one report that sprinklers had gone off, but no word on if all of them did. They might have been there for for than 'plumbing,' though. They might have installed other things, with their access to maintainance spaces. The suspect is the one who said he was a plumber; he might have been something else in maintenance. Elevators, electrical, etc.
After his arrest, Sakhera Hammad, 24, told FBI agents that he had a World Trade Center pass because he had worked as a plumber at the twin towers. He said he worked on the sprinkler system, and that Mahid Hammad also worked at the Trade Center.
Yup. Very curious. Why would the terrorists need 'scouts' just to blow up buildings with planes?
Why would the WTC hire these guys in particular, just for a one-time job? What was wrong that they were called in to 'fix?' Didn't the WTC have its own full-time staff of maintainance people?
Where did these men with the fake IDs live- in New York or Jersey? How did they come to know someone in Memphis, of all places?
They left NY on the days of the attacks. What were they doing from 9/5 to 9/11? Makes you wonder who the person was on the intercom that day that told everyone to go back to their offices, too.
So the terrorists were working on a "towering inferno" scenario only. In that case, to maximize the effects of the infernos, they would want someone to sabotage the automatic sprinkler systems. They would not need or want to carry in more demo to wreck the building: just turn some valves, or even change some signs to indicate "valve open" when it's closed etc. Or chain or lock shut some valves in dusty rarely visited maintenance rooms. A couple of "kryptonite locks" for example could delay the firefighters for a long time.