Nationals fan Gavin Rupp died earlier today after a three-year fight with brain cancer.

Background from the Washington Post:

In June, doctors informed Rupp and his family gioblastoma cancer had returned to his brain, and the location of the tumor made it inoperable. The Nationals learned about Rupp’s condition through his participation in Kyle’s Kamp, a youth baseball tournament that raises money for Children’s National Medical Center’s pediatric cancer research.

On July 5, Rupp came to Nationals Park with his family. Nationals coordinator of community relations Kyle Mann asked Harper if he could spend a few minutes with Rupp. Harper spoke with him for an hour and gave him signed bats and other equipment, including the hat off his head.

Tonight, after a 5-1 loss to the Detroit Tigers, Harper tweeted his condolences.