Tunnels can in some places be extremely hot, according to Lichten-"hot enough so that you could conceivably faint or get disoriented."
"It's a dangerous place to be if you're alone. There's a lot of high temperatures and lots of equipment," he says. "It's really just not a safe place to wander."
In Langton's book, the tunnels are used by the cronies of a fictional University President to plant dynamite under Sanders Theatre, and to poison a Sanders audience with carbon monoxide in the air ducts.
HUPD spokesperson Peggy A. McNamara says that in 1995, the tunnels were utilized in a real crime, a late-night burglary of two campus buildings. She would not release the names of the buildings.
Despite their checked past, the tunnels' mystique seems to be somewhat lost on Hawkes and Harvard's engineers, for whom the legendary Harvard underground is just a workspace.
"To us they're just utilitarian-we have a job to do in them," he says of the tunnels, but admits that he could see why some would be interested in them. "They're a part of this place, and a part of what makes this place work.