By Charlie De Mar

CHICAGO (CBS)–Dr. Tamara O’Neal was being remembered by her colleagues at Mercy Hospital on Tuesday for her contagious smile and her loving heart.

The day after O’Neal was fatally shot by her ex-fiance, Juan Lopez, in the hospital parking lot of the E.R. she worked in, her colleagues tried to make sense of a senseless tragedy. The shooting also claimed the lives of pharmacy resident Dayna Less and Chicago police officer Samuel Jimenez.

O’Neal’s colleagues agreed she always showed up to work with a big smile and an admirable work ethic. They said she was passionate about patient care and was an active church-goer.

Dr. Tamara O’Neal was fatally shot by her ex-fiance as she was walking to work at Mercy Hospital.

“Tamara exuded love,” said Dr. Marina Del Rios. “I’m still hoping that this is all just a nightmare.”

Dr. Heather Prendergast said she always started her shifts by sharing the message that it was going to be a great day.

That positive outlook on life is exactly what O’Neal’s former classmates at the University of Chicago also said they remember her for.

As word of the chaos and tragedy unfolded on Monday, Dr. Del Rios tried frantically to get a hold of O’Neal.

“I actually still have the text I sent saying ‘please let me know you’re OK,'” Del Rios said. “don’t think she ever got to see that.”

Dr. Prendergast said it was tough to come to the realization that O’Neal would never get to realize her dreams.

“She wanted to make an impact that obviously is gone now and that’s what hurts the most,” Prendergast said.

Charlie De Mar