Donald R. Horton, the founder of America’s largest homebuilding firm, died suddenly this week at the age of 74.

Horton founded D.R. Horton in 1991 in Fort Worth, Texas, but his tenure in the homebuilding business dates back to the early 1970s, according to a news release. He started D.R. Horton’s first predecessor company in 1978 and took the company public in 1992.

Executive Vice Chairman David Auld has been appointed to assume the late founder’s position as chairman of the board. Auld described his predecessor as a pioneer of the homebuilding industry, having shepherded unprecedented growth and helping more than 1 million American individuals and families achieve homeownership.

“We are all indebted to DR for his vision, tenacity and never-ending drive to continue to grow and improve our Company,” Auld said in a statement. “While he is impossible to replace, we will strive to carry on his legacy of enabling the dream of homeownership for individuals and families across the United States in every stage of their lives.”

The Arlington, Texas-based firm has been the largest homebuilder by volume in the U.S. since 2002 and has closed more than 1 million homes in its more than 45-year history, according to the release. D.R. Horton closed on 87,801 homes in the 12-month period ending March 31, in addition to more than 6,000 single-family rental homes and more than 2,500 multifamily units.

D.R. Horton’s fiscal 2023 revenue totaled $36B, placing it among the top five highest-grossing public companies based in the Dallas-Fort Worth metro, per WFAA.

The cause of Horton’s death was not disclosed. He is survived by his wife, Marty, two children and four grandchildren.