Laura Mulholland

Professor  was a scientist.

She was the inventor of the G-bomb. Before meeting the Second Doctor, the consequences of her creation made her hang herself several months after inventing the bomb. Her suicide note read "I was arrogant and blinkered enough to open Pandora's box. I cannot live with the demons I have released."

After meeting the Doctor, though, the cause of her death changed. The Selachians were going to take the last G-bomb, which was on the Triumph, and use it to destroy Earth. Unable to defuse it in time, she climbed on top of it with a grenade. She was gunned down by the Selachians, but not before activating the grenade. Four seconds later, the explosion cause the G-bomb to detonate, destroying the ship and all the Selachians on it. (PROSE: The Final Sanction)