Death tour

This 1979 novel is a classic of the "alligators in the sewers" genre. Sample dialog:

"I guess there are some down there."
"Alligators? In the sewers?"
"In the old pipe sections," she said. "Not in the plant. Down under."
"Alligators?" I repeated, like a halfwit. "In the pipes?"
"I guess people flush them down the toilet," she said.

Naturally the intrepid investigative team of five college students who call themselves Five Star can't resist seeing for themselves, and who can blame them? Do they find gators? Oh, yeah. But they find other things, too, things that are much, much worse. Do all five emerge from the underground? Of course not. And that's all I'm going to tell you.