Deb McKeever was picking up her mother-in-law after surgery at Johns Hopkins Hospital when a shot rang out down the hall. "We all got quiet," McKeever said Friday. "We were all really nervous, we really had no clue what going on ... I was thinking of Virginia Tech, Columbine — you don't know if he's going to come walking up the hall, shooting people or what." McKeever described the scene a day after Paul Warren Pardus, who was visiting his elderly mother in the same hospital, shot her doctor and then killed his mother and himself. McKeever told a 911 operator in recordings obtained by The Associated Press that she heard screaming down the hall as she and others barricaded themselves in a room after the gun went off. A physical therapist peeked into the hallway and then told McKeever, her mother-in-law, a nurse and an occupational therapist that there was someone shooting on the floor and to get back in the room. "My poor mother-in-law was bedridden, unable to walk, she was defenseless," McKeever said. A third caller told a 911 operator she was near Dr. David Cohen outside the eighth-floor room where the Pardus's mother was being treated. She heard a loud shot and saw him fall to the floor. "I was walking out and right next to me — it was loudest — it sounded like a shot," the unidentified woman told the dispatcher. "It was very loud and one of the physicians next to me went down saying, 'Help! Help! Help!'" And people that looked said, 'Go! Run! Get behind locked doors! Call 911!"