Dark Days (2000) on Netflix

Near Penn Station, next to the Amtrak tracks, squatters have been living for years. Marc Singer goes underground to live with them, and films this "family." A dozen or so men and one woman talk about their lives: horrors of childhood, jail time, losing children, being coke-heads. They scavenge, they've built themselves sturdy one-room shacks; they have pets, cook, chat, argue, give each other haircuts. A bucket is their toilet. Leaky overhead pipes are a source of water for showers. They live in virtual darkness. During the filming, Amtrak gives a 30-day eviction notice.