CHICAGO (CBS) -- As the timeline of the Mercy Hospital shooting unfolds, there's information about one of the victims.
Dr. Tamara O'Neal was apparently the target of shooter Juan Lopez. They were once engaged to be married.
Lopez confronted ex-fiance Dr. Tamara O'Neal in the hospital parking lot. She called 911 and reported the gun, bringing Chicago police to the scene. He shot Dr. O'Neal outside then he ran inside.
Lopez shot at two women getting off an elevator, killing pharmacy resident Dayna Less. He then went back outside, fired at squad cars that were shielding Dr. O'Neal's body. He headed back inside, and exchanged gunfire with police.
He was struck twice. Officer Samuel Jimenez was also killed during that exchange.
CBS 2 Investigator Dorothy Tucker has more on the doctor's life from the people who knew her well.
Shortly after Dr. O'Neal was shot, she was rushed to the University of Chicago Hospital. Not one but two of her closest friends were working and waiting on shooting victims. They had no idea she was one of them.
It's heartbreaking enough that Dr. Garth Walker lost his long time friend. He and Dr. Tamara O'Neal were medical school buddies at UIC. He knows her family. She attended his wedding.
"It's a true loss. I can't even put it into words honestly," said Dr. Walker.
So imagine his pain when he was working in the emergency room at the University of Chicago attending to the gun shot victims from the Mercy Hospital shooting when he learned one of them was O'Neal and she didn't make it.
"When they showed me the name I just lost it. I couldn't function any more," said Dr. Walker.
Dr. John Purakal was also in the ER. He and O'Neal were in the same residency class.
"We tried everything we could," Purakal said. "I wish I could have done more. I wish we could have prevented it and seen it coming."
Friends said they they were unaware of Juan Lopez's troubled history when the two met a little over a year ago.
"He made her happy. They loved each other," Walker said.
So much so they planned to get married.
An email sent to friends detailed the plans in South Bend, Indiana on October 27. It's signed "we can't wait to see you Tamara and Juan."
But a couple of weeks before the wedding it was called off.
When asked if she talked about any fears or concern, Walker said no.
"Not to me. Signals that this could have lead to something like this. Every time I met him he seemed like a nice individual," Walker said.
Walked added that he had asked O'Neal about the break-up and she promised to talk about it at a later date.
"One of the things that we lost was a black physician that was truly an inspiration to many women of color," Walker said.
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