Police said that on Saturday morning, linebacker Jovan Belcher shot and killed his girlfriend at a residence in Kansas City, then went to the Chiefs' practice facility outside the stadium and fatally shot himself as team personnel tried to stop him.
The Royals put this message on Twitter: "The @Royals organization sends our thoughts and prayers to the entire @KCChiefs family during this very difficult time."
Royals players, including designated hitter Billy Butler and pitcher Jeremy Guthrie, re-tweeted the expression of sympathy.
"Sad, sad news about the Chiefs player who committed suicide today. Keep him and the KC community in our prayers," tweeted second baseman Johnny Giavotella.
From pitcher Everett Teaford: "Thoughts and prayers go out to the Belcher family and the Chiefs organization, very sad situation."
"Sad to hear about the Chiefs player who took his girlfriend's life and his own ... thoughts and prayers for both families and those affected," tweeted former Royals infielder Mike Aviles.
This was the second suicide by shooting this year at the Truman Sports Complex.
On Sept. 14, outside Kauffman Stadium, a man shot and wounded a female parking lot attendant and then killed himself in an automobile less than four hours before the Royals' game against the Angels. The woman survived.
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.