Two security guards inside the Center for Advanced Medicine on the Barnes-Jewish campus fatally shot a 46-year-old man who flourished a pair of knives out of his pockets.
"It could have been a lot worse," said St. Louis Police Lieutenant Colonel Rochelle Jones.
Police said the incident happened on the 14th floor when the male patient armed himself with pocket knives in a public space of the floor. The guards fired several shots, killing him. He was pronounced dead at the scene.
"He refused to put the knives down, so, they had to take action," said Lt. Colonel Jones. "You have to act within a moment's notice, it's all based on what you see. Do you see a knife, a gun? It's just a few seconds to make a decision that will impact your life."
The man was with his wife at the time and was a patient at the center. No other information about the man was made available.
"I feel sorry for the family no telling what was going through the gentleman's mind or what kind of stress he was dealing with," said Center for Advanced Medicine cancer patient Chris Barnhart.
St. Louis Children's Hospital, which is adjacent to the Center for Advanced Medicine, was placed on lockdown as a result.
An all-employee alert was sent to hospital staff around 10:40 a.m. Thursday, adding the lockdown was a precaution.
The St. Louis Police Department's homicide division is investigating the shooting.