BRIGHTON PARK — An 18-year-old pregnant woman was brutally beaten by a man on a CTA bus as horrified passengers watched and some took video, according to officials and witnesses.

But the assistance of the bus driver — and a concerned witness — helped save the woman and her baby.

Brenda Torres, the pregnant woman, was on her way to work at 7:50 a.m. Monday when her Western Avenue express bus pulled up to the Western Orange Line station, 4900 S. Western Ave. A 21-year-old man on the bus was asked to leave, and on the way out, he turned and attacked the woman, unprovoked, punching her repeatedly in the face and head, according to police, the victim and a witness.

"It was like any normal day, and then everything changed," Torres said of the attack. "He just started hitting me. I just tried to cover my face. I was thinking, 'Oh my God, is he going to stop?' I just wanted someone to pull him off me."

The bus driver, a 39-year-old man, temporarily left the bus as he called authorities to help remove the unruly passenger, according to a witness. The driver heard screaming from inside and ran in and stopped the attack, the witness said.

The driver was battered by the attacker in the process, police said, but declined to be brought to an area hospital.

A CTA spokeswoman said the agency is assisting police in its investigation, including the review of surveillance footage.

A police officer, who was at the station and witnessed the scuffle between the attacker and bus driver, shot the attacker with a stun gun after he ignored commands, police said.

Steven Bailey, 21, was arrested in the assault, according to police. He has been charged with three felonies: aggravated battery to a pregnant woman, aggravated battery to a transit employee and aggravated battery in a public place. Bailey, who is hospitalized, is being held without bail, according to court records.

Brenda Torres, the pregnant 18-year-old attacked on a Western Avenue bus. [Provided/GoFundMe]

Torres does not know her attacker, but he did try to talk to her at the bus stop near 51st Street and Western Avenue, she said. He twice asked "Can I talk to you?" Torres said.

"I felt scared," she said. "I tried to ignore him."

Both Torres and Bailey got on the bus, with Torres sitting in the front seats reserved for pregnant women and those with disabilities. Bailey refused to pay the fare and sat in the back, and immediately began loudly talking and causing a disturbance, Torres and a witness said.

When the bus pulled into the Orange Line station, the bus driver walked back and said to the man, "'This is a good place for you to get off,'" said Christina Robles-Favela, who witnessed the attack.

The man refused and the bus driver left the bus and appeared to call authorities, Robles-Favela said. At that time, Bailey got up and walked to the front of the bus, as if he was leaving, but at the last minute, he turned and punched the pregnant woman, she said.

Steven Bailey, shown in a mug shot, is charged with three felonies after allegedly beating a pregnant woman and a CTA bus driver outside the Orange Line Western Station Monday. [Cook County Sheriff's Department]

"I'm expecting him to go out the front door, and he turns left and just starts wailing on this young girl," Robles-Favela said. "It was the worst thing I've seen in my life."

The attack was prolonged because the passengers, some who were screaming and seemed horrified, on the fairly crowded bus failed to intervene, Robles-Favela and Torres said. Many filmed the attack, they said.

One person screamed, "She's pregnant!" Robles-Favela said.

"'Nobody did anything?'" Torres said she remembers thinking after the attack ended. "I was just shocked when I saw how many people were there."

At least one person did call 911, witnesses said.

Robles-Favela said she began screaming and asked the man to stop. When the bus driver pulled the man off of Torres, she came in and provided assistance.

"She was begging, screaming crying. I'm begging him, too," she said. "Nobody was willing to pull him away. I was disgusted. I was willing to take the punches."

Robles-Favela was on her way home from work at an assisted living facility in Beverly, where she works the overnight shift. She had medical gloves in her pocket, so she put them on and tended to Torres, whose face was bleeding badly. Her hands and forearms, which she used to try to protect her face, were severely bruised and swollen.

"There was blood everywhere," Robles-Favela said. "She looked scared. She said, 'Please don't leave me.'"

So Robles-Favela accompanied Torres in the ambulance to Holy Cross Hospital. Torres did not suffer major injuries but, at first, doctors could not hear her unborn baby's heartbeat. Eventually, an ultrasound showed a heartbeat and Torres felt her baby boy kick, which doctors said was a good sign, Torres said.

"I'm so thankful," she said of the baby's prognosis. The baby is due in October.

After Torres's boyfriend didn't answer his phone and her mother was unable to stay at the hospital, Robles-Favela called her husband, and the two stayed with Torres until she was discharged later that day.

The Little Village couple is taking care of Torres, calling her work, offering transportation to doctor's offices and generally "opening up" their home to her. They have also launched a GoFundMe to help Torres while she's off work and for her medical expenses.

"How can a person be this nice?" Torres said of Robles-Favela. "I'm so thankful she was there."

After watching the attack and seeing a number of people refuse to intervene, Robles-Favela said her and her husband's efforts since then are the least they could do.

"That's not amazing. That's normal," Robles-Favela said of her efforts. "You see someone getting hurt, you should step in."

To make a donation to the victim, click here.