Ensign Ahni Jetal was a junior officer on the USS Voyager during its time in the Delta Quadrant. She was popular and well-liked among the crew; she was even friends with the senior staff. On her birthday, many of the senior officers organized a surprise party for her in the mess hall.
In 2373, she was piloting a shuttle on an away mission with Harry Kim when they were attacked. The alien attack injured both her and Kim with a residual energy charge, which had implanted an energy pulse that resided in her neural membranes. The pulse moved up her spinal cord and into her brain, resulting in death by massive synaptic failure. With no time to treat both patients, The Doctor was forced to choose to treat one of them over the other, and he picked Kim simply because he knew Kim better.
Her death later caused a contradiction in the EMH's programming due to the ethical issues involved in him 'choosing' to kill one person over another simply because of a personal connection, resulting in Captain Kathryn Janeway to order the erasing of The Doctor's memory of the event and his knowledge of Jetal. When the memories resurfaced again, Janeway decided to let The Doctor deal with the memories and try to work them out for himself. (VOY: "Latent Image")