Police immediately searched the hospital and secured the facility stating that at least one "possible offender is shot", according to police spokesperson Anthony Guglielmi. "At least one possible offender is shot", Guglielmi said.
Guglielmi said the gunman was killed, but it's unclear if he took his own life or was killed by police. She went to a window and saw someone running into the hospital.
"It's with profound sadness that we share the death of PO Samuel Jimenez from tonight's senseless active shooter incident", Guglielmi said.
One witness said he saw a man with a gun shoot a woman multiple times in a parking lot at the hospital. "I mean within seconds they were just surrounding the hospital, firefighters and ambulances, everything, they were just surrounding the hospital", she said.
A Twitter user posted video of what appeared to be Chicago police officers searching the interior of the hospital - and a blood trail on the hospital floor.
Two people were killed and two others critically wounded in a shooting at a Chicago hospital on Monday.
Multiple officers were seen waiting outside the emergency room as he was rushed into surgery.
Juan Lopez and Dr. Tamara O'Neal were scheduled to be married on October 27, 2018.
Maria Correa hid under a desk, clutching her 4-month-old son, Angel, while the violence unfolded.
A source in the Chicago Fire Department told NBC 5 the hospital had been partially evacuated. But since he had not been treated for his injuries, it became increasingly apparent that he had died from his wounds.
Target Will Have Spider-Man And A PS4 For $299
In the United Kingdom and Europe, you can get 20% off a 12 month PlayStation Plus subscription - that's £40 instead of £50. The Sony Black Friday discounts run from now until November 26 on games, and until December 2 on PlayStation VR bundles.
Brexit: two-year transition period could be extended
Luxembourg's foreign minister says there is "no better" Brexit deal for Britain than the one that was finalized last week. In Brussels, Austria's minister for Europe, Gernot Bluemel, struck a more melancholy tone.