Chicago has been experiencing an alarming increase in crime this year. Yet some Chicagoans refuse to be victims.

On a Chicago train early on Monday, a robbery victim fatally stabbed a 15-year-old boy who pulled a gun on him. This is the second incident in three days that a city train passenger has resisted an assailant with a knife.

Just after 3 a.m., a guy was on a Red Line train at 63rd Street when a group of seven people approached him. One of the group, a 15-year-old lad, pulled a gun in an apparent robbery attempt, according to WBBM-TV, quoting Chicago Police Chief of Detectives Brendan Deenihan.

"So, this person is aboard the train. There are seven people in this group. Based on the information [Chicago Transit Authority] has shown us, one of them pulls out what seems to be a handgun. The individual who seems to be being robbed then pulls out a knife and stabs the other person with the gun. Now that guy has passed away, "said Deenihan.

The station reported that the stabbed youngster fled for help and made it to the 6300 block of South Yale Avenue before collapsing. He was taken to the University of Chicago Medical Center, where he passed away.

According to WBBM, Deenihan said, "When that person is leaving, they drop the gun somewhere. One of the other people in the group with that person then picks up that alleged weapon and escapes the scene. Everyone fled the scene."

Detectives are trying to identify everyone who was part of the crime, Deenihan told the station, adding that no one has been arrested.

According to WBBM, Police Superintendent David Brown stated that "these criminals need to be apprehended and brought to court to make it known you will be held liable for any crimes that take place on the CTA."

The station said it was the second incident in three days that someone had defended himself aboard a Chicago train using a knife.

Six armed criminals accosted and attempted to rob a train passenger early on Friday. However, the victim drew a knife and retaliated. In the end, all six suspects were apprehended. Three suspects suffered injuries and were hospitalized, but the victim also required medical attention.

According to CTA Vice President of Security Kevin Ryan, self-defense aboard city trains is not advisable: "Do not fight back - the Chicago police will advise you. Be compliant. Don't put yourself in danger by doing anything more."

Ryan informed WBBM that the CTA system has up to 250 unarmed security personnel patrolling it daily. The station's goal is to have 300.