Oliver Morgenstern

Oliver Morgenstern was a medical student at Royal Hope Hospital. He was on duty in the hospital when it was transported to the Moon by the Judoon in 2008.

He kept following the Judoon captain and reassuring the patients that they were safe. When the hospital was returned to Earth, he was interviewed on the radio about the experience. (TV: Smith and Jones)

Alternate timeline
In an alternate universe which Donna Noble created by turning right to the wrong job interview, the Tenth Doctor died on 24 December 2007, and he was not able to save anyone in the Royal Hope.

Oliver was the only survivor as Martha Jones gave the last of her oxygen to save him. (TV: Turn Left)