Leo Welt was one of the kids of Berlin, orphaned in the aftermath of World War II, not exactly a street urchin but certainly a young wheeler-dealer who peddled black-market goods to survive.

His father, a German Jew who was a Berlin newspaper reporter, died in a concentration camp in 1942. His mother, a Catholic, kept her family together through the bombings of the city, then died of tuberculosis just after the war. The preteen Welt saw a brother and sister run over by a Soviet army transport truck as he huddled against a wall on a narrow street.

Few could have predicted that Welt, whose life started in such turmoil, would end up as a successful international trade expert who opened an office on Washington's lobbyist-heavy K Street, who introduced executives to ambassadors and who rescued the fire-damaged U.S. Embassy in Moscow with the timely loan of a crane. He died of cancer Aug. 5 at his home in the Wesley Heights section of Northwest Washington at age 70.

"He was undoubtedly courageous and at times could be ferocious," said his son, Bruno Welt. "But he had unbridled energy and a dedication to success."

Leo Gerhard Bruno Welt did not forget his past. Every morning since 1987, he made time to pick up day-old bread from the Corcoran Street Safeway to deliver to a downtown D.C. soup kitchen. At a charity ball for CARE in 1981, he told a newspaper reporter that he remembered when he, then living in a Berlin orphanage, got a message that a package waited for him across town. "It was so heavy. Filled with powdered milk, margarine, eggs, flour, sugar. And a carton of cigarettes. They were more valuable than money. They were money." The package came from "some lovely family in Nebraska. I took the package home. . . . They were great, those packages. And I got a lot of them, too."

In 1950, when he was 16, Catholic Charities sent him to the United States. While on a layover at Shannon International Airport in Ireland, he was approached by an English real estate developer. Welt, a handsome, dark-haired and dark-eyed youth, reminded the man of his son who had died in World War II. They spoke in German, and the man gave him a phone number to call when he reached New York.

Welt made the call. A limousine appeared; he was whisked away to a penthouse on Park Avenue for tea and a roast beef dinner. Among the guests that night at dinner was the Kessler family, which had made a fortune in glass and lamps. The Kesslers adopted him and found themselves with a smart, ambitious son who taught himself English by copying Charles Dickens's "A Tale of Two Cities." The Kesslers taught him to dress properly (his new mother insisted on at least one striped tie among the wild flowered ones he favored) and insisted he abandon his plans to become an auto mechanic to attend college. He gained admission to Princeton University.

His whirlwind worldwide career began with a job at International Paper, then Weyerhauser and Rockwell International. He lived in Beirut, Nairobi and Moscow before moving to Washington in 1977.

His outsize personality, enthusiastic embrace of life and bald head made him instantly noticeable when he walked into a room, friends said, and his confidence was legendary. He married, had two children, divorced and had a long-term relationship with another woman. He remained a presence in the lives of his children.

His daughter, Sabina Welt, remembered getting a call from her excited father one day in 1989, announcing that she and her brother would be off school for a few days to fly to Berlin. Welt had heard that the Berlin Wall was about to fall, and he wanted them to be there.

Welt started a consulting firm in 1968, and for almost 30 years he represented U.S. corporations in the Soviet bloc and in China and Vietnam. It was a successful venture; he won two major awards from the Commerce Department.

Welt was representing the Milwaukee heavy-equipment company Harnischfeger Corp. at a trade show in Moscow in fall 1977. A fire had destroyed the top floors of the 10-story U.S. Embassy in Moscow that summer, and the Russians were unable or unwilling to provide a truck crane big enough to lift material to repair the roof.

The Russian winter was fast approaching when Ambassador Malcolm Toon happened by the trade fair and spotted Welt and the self-propelled Harnischfeger crane, which was the size and weight of a tank. With its 178-foot boom extended, the Harnischfeger could lift three tons of material at a time. Some 30 tons of roofing material was due to arrive from Finland that day, The Washington Post said.

Welt immediately agreed to help. It was not a decision without risk, his friend Jim Schroeder said recently; the Soviets later made him persona non grata for the action. But Welt, the former apprentice auto mechanic who had never rigged or driven a crane, found an owner's manual in the glove compartment of the cab. He and a Navy Seabee from the embassy got it started, then drove it through the streets of Moscow to the embassy.

"When they got the crane back to the exhibition," said Sabina Welt, "the story goes that the Russians wouldn't buy it, because now it was considered used."

It's unlikely that setback bothered Welt for long. His life had taught him not to worry about temporary problems.

Leo Welt, an international businessman, brought his children back to his native Berlin in 1989 to watch the fall of the wall that divided the city and, at left, chipped away at the wall himself.