CHICAGO (CBS) — Newly-released surveillance video showed people running and ducking for cover during a shooting along the Chicago River downtown last weekend.

Police released the video Wednesday in hopes of identifying possible witnesses or suspects.

Investigators are zeroing in on two men who are seen on the video possibly holding guns.

One woman and one man were killed in the shooting early Sunday morning.

They were found in a car in the 0-99 block of East Wacker Drive near Wabash Avenue around 2:30 a.m. Sunday when they waved down officers for help, according to Chicago Police.

Police said a quarrel between an unidentified man and a group of people led to that same man taking out his gun.

“‘Boom! Boom! Boom!’” said witness Travis Whitaker. “Next thing you know, shorty’s laying there.”

The 35-year-old man was shot once in the neck, and the 25-year-old woman was shot once in each arm. Both were taken to Northwestern Memorial Hospital, and the man died a short time later. The woman was reported in good condition.