Chapotraphouse

Tbh the urban design of most of the US is basically perfect to ambush groups walking down the streets. Big, mostly empty streets surrounded by one or two story houses that are typically above street level and easy to exit the sides or rear or get off the roof.

Two riflemen crossfiring could decimate a squad and be out the back door before anyone knew what happened. Even just a lone shooter with trigger discipline could do a lot of damage. I've always been surprised it doesn't happen at all.