Lieutenant Natasha Yar, better known as Tasha, was a Human Starfleet officer born on Turkana IV, and former security chief on the USS Enterprise-D. Unfortunately, Tasha was killed not even a year into the Enterprise's mission.
She was fondly remembered by the Enterprise crew, and an alternate timeline version of Tasha indirectly played a very important role in Romulan politics.
Despite a valiant effort by Dr. Crusher, on SD 41601 during a rescue mission on Vagra II she died as a result of injuries from an invisible energy bolt to her head by the malevolent creature Armus; it left a blotch on her jaw. A memorial service that featured a holographic recording of her last thoughts and thank-yous to her closest shipmates was held later.