This was an alleyway.
Walkers corner Glenn and Nicholas in an alley. Glenn climbs a dumpster and helps Nicholas up, as walkers surround them and grab at their feet. After staring at the teeming horde all around them, a sudden calm comes over Nicholas. "Thank you," he tells Glenn and shoots himself in the head. Glenn gets knocked into the herd by Nicholas' falling corpse and screams as he is swarmed by the herd of feasting walkers.
In the alley where Nicholas and Glenn tumbled off a dumpster into a herd of walkers, Glenn lies pinned underneath Nicholas' body as walkers disembowel it. Eventually, Glenn squirms to safety underneath the dumpster, stabbing at the walkers reaching for him until their corpses block him in.
Days pass as Glenn waits for the herd to move on. Finally, he crawls out and searches for water. "Heads up," says a voice, moments before a water bottle hits the ground. It's Enid, who is standing on the roof of an adjacent building. She tells Glenn that Alexandria was attacked, but runs away before he can question her further. Glenn chases Enid into the street, but loses her.