A fatal police shooting that froze the center of San Francisco Wednesday had its roots in an argument over a Subway-brand sandwich, a witness says.

As you likely know, the San Francisco Police Department says that officers walking a footbeat on the 900 block of Market Street at 11:22 a.m. Wednesday "observed a white, male subject stabbing an Asian or Filipino male."

"The officers intervened and at least one officer discharged a firearm," police say, striking the stabbing suspect. He was pronounced dead at the scene, and was identified Thursday morning by the San Francisco Medical Examiner's office as 26-year-old Nicholas Flusche. As of publication time, his city of residence was unknown.

A photo tweeted from the scene depicted a bloody man in a Subway uniform seated on the Market Street curb, spurring rumors that the shooting occurred at the Subway sandwich shop on the same block where the shooting occurred.

Giving weight to the Subway hypothesis, the SF Chronicle reports that "investigators could be seen going in and out of the Subway on Market Street near Turk Street."

ABC 7 reports this morning that the situation began when an "argument between a Subway employee and a man broke out Wednesday morning, possibly over a sandwich."

"All I hear is two dudes arguing and then the cops was showing up," area resident Johney Jimenez tells ABC 7.

"And then they started arguing and telling him to get down. Just like hella nonsense."

Jimenez says ""I heard like two [shots], that's all I heard." He says he also "saw a four-inch knife afterward."

According to SFPD spokesperson Sergeant Michael Andraychak the stabbing victim is currently being treated at an area hospital for non-life threatening injuries.

SFPD's Homicide and Internal Affairs divisions, the San Francisco District Attorney’s Independent Investigations Bureau, the Department of Police Accountability, and the Medical Examiner’s Office are all investigating the shooting.

Speaking with ABC 7, David Salaverry of San Franciscans for Police Accountability says "as soon as we see the body cams we're hoping they're in alignment with what the police have said so far."

"If so, this may have been an unavoidable shooting," he said

As of Thursday morning, however, it's unclear if police body cameras captured the incident. According to ABC 7, investigators pulled video from a Muni bus that passed the incident as it was underway, but no other information on footage from the shooting has been released.

Previously: SFPD Confirms Fatal Police Shooting On Market Street