These are mole people, you dummy.
There’s no question that there are small numbers of homeless people living in tunnels. There was even a documentary film, Dark Days, that followed the lives of several people in the train tunnels near Penn Station.
OTOH, Toth’s book consists entirely of describing tunnels, infrastructure, and abandoned stations that don’t exist, of talking to people that don’t exist, describing complex social hierarchies amongst impossibly large tunnel-dwelling societies that don’t exist, credulously repeating tall tales about blind people with webbed feet, and recounting weeks worth of adventures that could not have possibly occurred. IOW, she is full of shit.