Disturbing video shows a mob of teen e-bikers brutally beating a random stranger as he walked home through an affluent California neighborhood — then taking a photo, thinking he was dead.

The victim, only identified as a man in his 60s, was walking home in Hermosa Beach, California, late Friday when a group of about six thugs surrounded him, with one asking for the pizza he was carrying, surveillance footage shows.

As he responded, the others closed in and began punching, kicking and stomping him on the ground — with one bashing him over the head with his pizza box, the footage shows.

The attackers then fled on their e-bikes, with some saying they assumed their victim was dead — but with one snapping a photo of him anyway, according to KTLA .

Moments before the attack, the teens were

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