A woman walking on a busy Boston street was attacked by four thugs, but instead of anyone running to help, passersby simply ignored her plight.

During the incident, which was captured by surveillance video, the victim holds on tight to her red handbag as her assailant tries to grab it. Three others join in as the two play tug of war with the satchel. She eventually falls to the ground and gets kicked and punched.  Finally, the woman manages to walk out of frame, with her bag in tow.

ABC News Boston affiliate WCVB reported the incident happened on Huntington Avenue just before noon on Monday.

Other bystanders who observed the scuffle keep walking, opting not to get involved. Two men eventually emerged from what appears to be a nearby store, but at that time the fight – which lasted less than a minute – had already broken up.

Police are now asking for the victim or witnesses to come forward.

The “bystander effect,” a psychological phenomenon where people fail to act instead of listening to their moral compasses, is a common inhibitor of altruism. Psychologists have demonstrated that if one person is spurred to take action, others will follow. But if nobody makes that first move, others may not either.

One of the most notorious examples of this was the recent incident in China where a toddler was run over not once, but two times, and ignored by at least 18 pedestrians and cyclists. She died days later.

Last year, more than 20 passersby walked past a homeless man who lay bleeding on a New York City sidewalk.

But for many of the missed opportunities, there are heart warming stories about people who have stepped up.  And in the case of the woman attacked in Boston, police are hoping a witness will come forward now, and do the right thing.