Officers rushed to the celebrated hospital and medical centre amid reports of multiple casualties after a suspect entered the facility on the city’s South Side and started firing. It was reported the suspect, said by CNN to be a 32-year-old man, was killed in the incident, though it was not immediately clear if he had taken his own life or was shot by police. Some unconfirmed reports said his primary target was his ex-fiancee.
Anthony Guglielmi, chief communications officer for the Chicago Police Department, tweeted for people to “avoid area. Heavy police response incoming”.
A police official told NBC News that the hospital had been partially evacuated, while officers searched the premises. Some people were hiding in locked rooms. A nearby school was also placed on lockdown for a period, though students were later allowed to go home.
Mr Guglielmi named the killed Chicago police officer as Samuel Jimenez. He tweeted that "three innocent victims and the cowardly gunman who deserves to be nameless were killed tonight".
To see how events unfolded see our live coverage below
A police official told the local NBC News affiliate the hospital has been partially evacuated, but comments on social media suggest some people are still in the building (see the below post).
A Chicago Police spokesperson told USA Today that shots were fired both inside and outside of the hospital.
It remains unclear exactly how many victims there may have been in the shooting. At least one possible offender has been killed, a police spokesperson said.
A witness says he saw a gunman repeatedly shoot a woman outside a Chicago hospital before making his way inside and opening fire. James Gray tells KABC-TV he was inside Mercy Hospital on Monday when the shooting unfolded. He described the scene as "mass chaos", the Associated Press said. Gray says the man was walking with a woman near a parking area when he turned and shot her in the chest multiple times. He says the man then stood over the woman and continued shooting.
