US President Barack Obama has said he is “heartbroken” after a senior White House employee was killed on a charity bike ride.
Jake Brewer, 34, died while taking part in the 150-mile Ride to Conquer Cancer event on Saturday.
The senior policy adviser in the chief technology office lost control of his bike and was hit by a vehicle.
Mr Obama said: “Jake devoted his life to empowering people and making government work better for them.”
He said Mr Brewer had “a brilliant mind, a big heart, and an insatiable desire to give back”.
“He worked to give citizens a louder voice in our society. He engaged our striving immigrants. He pushed for more transparency in our democracy. And he sought to expand opportunity for all.
“I’ve often said that today’s younger generation is smarter, more determined, and more capable of making a difference than I was as a young man. Jake was proof of that.”
Mr Brewer, from Alexandria, Virginia, reportedly lost control of his bike on a sharp curve in Howard County, Maryland.
His wife, journalist Mary Katharine Ham, posted the news of the death on Instagram.
“I will miss him forever, even more than I can know right now,” she wrote.
The president said he and is wife would be praying for the Brewer family, adding: “They’ll always have a family here at the White House.”