One man is dead, and another was injured after a shooting on the CTA Pink Line train in The Loop early Tuesday morning. 

Chicago police said just before 1:30 a.m., two men, 23 and 44, were on the train in the 100 block of North Wells Street when they were arguing with another man who was armed with a knife. 

Police said the argument turned physical, and one of the victims took out a gun, during which the man took the victim's gun and fired shots. 

One woman told CBS News Chicago that she watched one of the victims collapse off the train and didn't hesitate to step in.

"Thank God we was coming that way. " I wouldn't know what of had happened while he was," T. Barrett said.

She said she was on her way home when she saw a young man fall off the train, bleeding heavily from his wrist and calling for help.

"I think he said he'd been shot, and when I got to him. Next minute I know, I saw a lot of blood rushing down his hand," she said.

Without thinking twice, she ran over, taking off her own shirt to use as a tourniquet, applying pressure until the police arrived. She credits her nursing training, as she helped to slow the victim's bleeding. 

"I had to make sure he was okay," Barrett said. 

The 44-year-old man was shot in the abdomen and taken to Northwestern Hospital, where he was pronounced dead. The Cook County Medical Examiner's office identified the victim as Raymond S. Harrison of Chicago.

The 23-year-old man was taken to the same hospital with a gunshot wound to the wrist. No other injuries were reported. 

Video from the scene taken around 1:30 a.m. showed CPD officers canvassing the area around Wells and Randolph streets, and investigating inside a train car with evidence markers next to shell casings.   

As of Tuesday afternoon, police said no arrests were made in the case.

On Friday, the CTA submitted a safety plan in response to threats made by the Trump administration to withhold funding should the CTA not improve safety. However, the Federal Transit Administration said that won't be enough, and is giving the CTA 90 days to respond with a better safety plan, or risk having $50 million cut from the agency. The FTA cited last month's attack on a 26-year-old woman, who was set on fire on a Blue Line train in downtown Chicago, in making their demands.  

Mayor Brandon Johnson says it's going to take funding to create change on public transit.

"As I've said repeatedly, that's mental health support services, and yes, that means having strategic deployment of law enforcement that plays an incredible role," he said.

As for Barrett, she said she won't take public transit out of fear, but was happy to be there to help the victim. 

"You could be coming from work, you could be coming from school or anything, and stuff like this happens," she said. "I'm just glad that he's okay."

Barrett mentioned that the two victims wore Five Guys uniforms at the time, but it is unclear if either victim worked there. 

Chicago police are asking with information to come forward as investigations remain ongoing.