The doorman of a building located in Chicago's Gold Coast neighborhood talks about how he stopped an attempted sexual assault in an alley near his building on Sunday morning. (Nancy Stone/Chicago Tribune)
Cornell Wrightington may not look like a hero.

The father of two girls is soft-spoken and wears crisp white shirts in his job as doorman at a Gold Coast condo building. But at dawn Sunday, while working an overnight shift for a friend, Wrightington rushed to the rescue of a young woman who was being assaulted in an alley.

“I saw somebody who needed my help,” Wrightington, 44, said Monday. “I was just fortunate I was covering a shift for someone.”

Wrightington said he was sitting in the glass lobby of the building at 30 W. Oak St. around 5:40 a.m. when he noticed a young woman walking past his building and talking on her cellphone.

Then Wrightington spotted a man who walked across the street and started following her from a distance.

“When she would slow down, he would slow down,’’ he said. “Something was wrong with that picture. … She didn't notice him, but I noticed him. It was the way he was behaving and his demeanor. He was fidgety and nervous.”

The woman cut through an alley behind the building and headed toward Maple Street.

The man walked passed the alley and then did something that really caught Wrightington's attention. “He doubled back’’ and disappeared into the alley, Wrightington said.

Without thinking, Wrightington said he ran to the alley. “I saw her feet kicking and heard her screaming, ‘Please don’t hurt me, please don’t rape me’’’ he said.

He rushed down the alley and saw the man on top of her. He had removed his navy T-shirt and was holding it over her mouth to muffle her screams.

“I heard her begging and pleading not to do this, so I ran up on him and yelled at him,’’ Wrightington said. “I ordered him to get up off her and let her go.”

“When he saw me, he got off her and took off running,’’ said Wrightington, who added that the attacker fled north onto Maple Street.

Wrightington said he ran to the woman’s side. “I said: ‘Come with me, you’re not OK,” said Wrightington, who walked her to his lobby, where she called her sister and he called 911.

Police said the attacker is also suspected of attacking a woman June 17 in the 1100 block of North Clark Street, about two blocks from Wrightington’s building.

An attacker approached that woman from behind as well and pulled her into an alley and sexually assaulted her.

Police described the attacker as a black man between the ages of 35 to 45. He has a dark brown complexion and is about 5 feet 9 inches to 6 feet 2 inches tall.

He weighs 240 to 260 pounds, police said, and was last seen wearing a dark blue tank top, white shirt and blue-jean shorts.

Throughout the day Monday, residents kept congratulating Wrightington, calling him a hero. One man leaned out a balcony and clapped and gave him a thumbs-up as he walked through the alley.

But Wrightington downplayed the praise.

“I thought about my two daughters, I wouldn’t want something like that to happen to them,’’ he said. “I wasn’t scared that he (might have) had a gun. I wasn’t thinking about that at the time.”

rsobol@tribune.com