CHICAGO (CBS)– Steve White has lived in Chicago for 50 years and says he has never seen anything like the shooting that took place Monday on the Mercy Hospital campus.

Four people were shot after a gunman opened fire Monday afternoon. Sources say the gunman first targeted a woman in the parking lot and then entered the hospital.

White was visiting Mercy Hospital for dehydration.

He said when individuals in the emergency room heard shots coming from parking lot, they all rushed to the window. The hospital went into lock-down when the gunman came inside the hospital through the main entrance.

“It scared everybody,” White said.

He saw the gunman firing shots and one of the victims on the ground. White saw the gunman turn to a woman in hospital scrubs and start shooting and he says he heard, “pow, pow, pow.”

“He was aiming at somebody, maybe it was his girlfriend, I don’t know what is was,” White said.

The emergency room patient said everyone inside the hospital was nervous and some were crying. In all the commotion, he lost his wallet.

“I have never seen nothing like this in my life,” he said. “This is crazy”

The emergency room patient was saddened by the timing of this incident.

“Around Thanksgiving, that’s the sad part about it and at a hospital,” White said. “Why would you go to a hospital and kill some innocent people?”