Surveillance video shows a man grabbing a chair off the street at 370 W. 58th Street near 9th Ave and hurling it at a 66-year-old man.
It happened Friday around 10:30 p.m.
The force of the blow was so hard, the victim suffered a broken arm.
The victim also dropped his cell phone during the attack.
The suspect grabbed it and ran off.
Police are asking for the public's help tracking down the suspect.
Call the NYPD's Crime Stoppers Hotline at 1-800-577-TIPS (8477) or for Spanish, 1-888-57-PISTA (74782). You can also submit tips by visiting the CrimeStoppers website at crimestoppers.nypdonline.org or by messaging on Twitter @NYPDTips.
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