NEW YORK (CBSNewYork) — A Queens man is clinging to life after a thief punched him so hard, his head slammed into a sidewalk.

As CBS2’s Marc Liverman reported, it was all over a cell phone.

66-year-old Mohammad Alam was captured on surveillance video last Thursday sprinting down Hillside Avenue in Jamaica when within seconds, a suspect standing in front of M/M Wireless and Computer USA Company reached over and punched him in the head.

Mijanur Mallik was working inside the store.

“We listen to a sound and we go outside and found that the guy is falling there and his face is up and after that my cousin called police,” he said.

Another witness told police they saw a group of teens in a nearby store asking about cell phones earlier in the day. There was some kind of confrontation, then a few minutes later that witness saw the victim chasing one of those teens down the street.

That’s when another teen threw a punch. What you don’t see on surveillance video is Alam sprawled across the pavement and barely able to move.

First responders rushed to the scene.

“He’s very friendly, he talked with us and it’s very bad news for us,” Mallik said.

Mallik and coworker Rashid Jamal say the victim would always come into their store. He’s now fighting for his life at NYC Health+Hospitals/Elmhurst.

“Everybody feels bad,” Jamal said. “This community feels bad.”

Police say the attacker and four other teens got away, even after another witness tried to hold onto the attacker.

Jamal tells CBS2 the incident has him so scared, he’s closing the store earlier every night.

The number of reported cases of felony assault for the 170th Precinct in Queens is up 22 percent year-to-date, CBS2 reported.