The Latest on the death of billionaire David Koch (all times local):

9:45 a.m.

Billionaire conservative donor Charles Koch is remembering his brother David Koch for "his giant personality and passion for life" and says he will be "greatly missed, but never forgotten."

Charles Koch and David Koch together were major donors to conservative causes and educational groups. David Koch died Friday at age 79.

Charles Koch says his brother was diagnosed with advanced prostate cancer 27 years ago but liked to say that "brilliant doctors, state-of-the-art medications and his own stubbornness kept the cancer at bay." Charles Koch says his brother "was able to touch so many more lives as a result" in the ensuing years.

He says his brother got married, had three children and remained dedicated to Koch Industries, based in Wichita, Kansas.

The brothers each had an estimated net worth of $50.5 billion, tied in 11th place in 2019 on the Forbes 500 list of the nation's richest men.

9:05 a.m.

Billionaire David Koch has died at age 79. Koch was a major donor to conservative causes and educational groups.

His older brother, Charles Koch, said on Friday, "It is with a heavy heart that I now must inform you of David's death."

The Kochs were best known for a vast political network they built that became popularly known as the "Kochtopus" for its far-reaching tentacles in support of conservative causes.

The brothers founded the anti-tax, small government group Americans for Prosperity.

David Koch was an engineer trained at the Massachusetts Institute of Technology. He joined Wichita, Kansas-based Koch Industries in 1970 and served on its board. He was chief executive officer of Koch Chemical Technology Group, a Koch subsidiary.

Charles and David Koch each had an estimated net worth of $50.5 billion, tied in 11th place in 2019 on the Forbes 500 list of the nation's richest men.