The man who built Hanford died late Friday night.

Franklin T. Matthias, 85, died in his sleep shortly before midnight at the San Marco nursing home in Walnut Creek, Calif., his son, Michael Matthias, said Saturday.

Matthias had been diagnosed with massive cancer in his lungs, liver and pancreas about six weeks ago, his son said.

He is the second major figure in Hanford's construction to die in recent months. Gil Church, the head of Du Pont's team at Hanford during World War II, died in October. Du Pont was the prime contractor for the Hanford Engineer Works. This year marks the 50th anniversary of the start of the project.

Perhaps to a degree greater than any other individual, Matthias shaped the destiny of the Mid-Columbia.

In 1942, he was a 34-year-old lieutenant colonel at the Army Corps of Engineers headquarters in Washington, D.C., tracking funding for the new Pentagon building and other military construction projects throughout the United States.

There he caught the attention of Gen. Leslie Groves, head of the Manhattan Project, the U.S. effort to develop a nuclear bomb during World War II.

Groves sent Matthias out West to scout locations for the nation's first plutonium production site.

On Dec. 22, 1942, Matthias took off from Yakima in a small military observation plane. As he flew over the small towns of Hanford and White Bluffs, Matthias knew immediately he had found the spot.

A few weeks later, Groves sent Matthias back to the Mid-Columbia to manage the coming construction project. Still a few weeks shy of his 35th birthday, Matthias moved to Pasco and set up shop in a little rented garage a block away from the train station. It was headquarters for the Hanford project for the next six weeks, until an office could be erected at the construction camp.

Matthias would head up the massive effort for the next three years. Some 150,000 workers would contribute to the project, with the peak work force reaching nearly 50,000 in 1944. In 30 months they would build 554 buildings, 386 miles of road, 158 miles of railroad, three massive chemical plants and the world's first three production-scale nuclear reactors.

Plutonium from Hanford would produce the Trinity blast at a test site in New Mexico, the world's first nuclear explosion.

Hanford plutonium also was in the last nuclear bomb used in war. On Aug. 9, 1945, the bomber Bock's Car dropped the Fat Man bomb on Nagasaki. The bomb destroyed 44 percent of the city, killing 35,000 and injuring another 60,000.

Within two days, the Japanese government began negotiating a surrender.

"I never had any reluctance nor any thought later that I didn't follow the right course. There were never any questions in my mind," Matthias told the Tri-City Herald earlier this year.

"The American invasion was planned to start about three weeks after the bombs were dropped. I think the official Army estimate was a million of our casualties and probably twice that many Japanese. We saved them by three weeks."

Matthias was awarded the Distinguished Service Medal, the nation's highest military honor for service other than on the battlefield, for managing the Hanford Engineer Works.

At the end of World War II, Matthias went to Brazil, where he built hydroelectric dams. He stayed in heavy construction all his life. He was vice president at Kaiser Engineers when he retired after 50 years in engineering.

He is survived by his son, Michael, of Santa Cruz, Calif., and brother, Carl Matthias, of Norfolk, Va. Hull's Walnut Creek Chapel, in Walnut Creek, Calif., is in charge of funeral arrangements. The family requests memorial contributions be made to the American Cancer Society.