Hospital spokesman Gary Stephenson says the shooting was on the eighth floor of the main hospital building. He says that floor remains locked down. Earlier, Baltimore police said the hospital was being evacuated.
Police say they do not know the doctor's condition. However, the Baltimore Sun reports the doctor is in critical condition.
Portions of the Nelson Building, a thoracic center on its sprawling East Baltimore campus, have been placed on lockdown and other sections have been evacuated, the Sun reports.