The first pains came before 8 a.m. The woman who lived in the tunnel had been out gathering blankets and pillows all night. But then, the contractions started. It was 92 degrees out, and she was 8½ months along. She’d never seen a doctor. When a group in neon shirts offering homeless services came through the tunnels, she was whimpering for help. The neon team called an ambulance. Nearly a year to the day after the tunnels claimed one life in the flash floods of an early monsoon season, another tunnel under the Strip began ushering in a new life....