When the first news of the fire in the American embassy in Moscow appeared on television last summer, Carl Hansen, 68, started packing his bags and closing up his Silver Spring house.

The TV news program was still on when the call came from the State Department. And the night-long fire in the U.S. embassy was still blazing when Hansen, four Seabees and four Marines were winging over the Atlantic on the 4,800-mile flight to Moscow.

A structural engineer, Hansen has devoted his life to uplifting things like columns, beams, joists and trusses. As a young man, he helped design Fort Knox and the Denver Mint, has built or restored hundreds of office buildings, schools, embassies and steepled churches here, diagnosed the case of the crumbling concrete at RFK Stadium and has visited more than 25 foreign countries in the past two decades when an earthquake or other natural or unnatural disaster has struck State Department buildings abroad.

One of Hansen's recent jobs as sexagenarian State Department troubleshooter took him to Havana, where he checked the empty U.S. embassy building against the time American officials may return to Cuba. It is in good shape, although the metal-framed windows have corroded in the salty harbor air, he said.

Last spring, following a severe earthquake in Bucharest, he spent one and a half weeks checking for structural damage in every U.S. embassy and chancery building in the Rumanian capital, as well as the homes of all U.S. officials.

"Every building in town had structural damage and our people were very nervous," Hansen said. "Some buildings had cracks big enough to stick your hand in and they wanted to know if the buildings were safe . . . especially since another earthquake was predicted. They were, but all I could do was look upstairs and make a guess, an educated guess."

Then, because Hansen already was over there and they were nearby - relatively nearby - he was sent to Budapest, Stockholm, Copenhagen and Istanbul to check out assorted buildings.

While one of the few structural engineers to make foreign house calls for the State Department, Hansen is not the only specialist called in emergencies. He is, however, one of the oldest and has been doing it longer than any of the others, a spokesman for the State Department's foreign buildings operations said last week.

"We have a dedicated staff of four architects and four engineers here, but we are responsible for consulates, embassies and other buildings in more than 100 countries around the world . . . and frequently we need outside specialists such as Carl Hansen. He is extremely conscientious and highly responsive when we need him. Another reason we called Hansen in the Moscow fire was that he was familiar with the embassy because he'd been there before," the spokesman said.

Hansen, a small, modest man who insists he doesn't "want it to appear I'm the only engineer in town or the best," quickly designed a new roof for the 10-story Moscow embassy, with building materials flown in from Finland and half a dozen other European countries. It was completed "on Sept. 21, just before the snow started flying . . . and once it starts, it snows until May," said Hansen.

The race with winter was won with the help of a 178-foot American-built crane that just happened to be on display at a Moscow trade fair. It was borrowed for a day by Hansen and the Seabees, trundled through the streets of Moscow, and used to hoist heavy building materials to the top of the embassy.

While the life of a structural engineer frequently is filled with frantic calls following fires, earthquakes and other calamaties, Hansen's engineering career began peacefully in 1931 in Washingtons citadel of engineering, "the old supervising architect's office, the great grandaddy of GSA (General Services Administration)," said Hansen.

"In the old days, we designed most government buildings. I did a good bit of structural work on the Fort Knox gold depository and the Denver mint . . . and I guess I did a post office in every state," said Hansen. "But one weak point was you couldn't get out to see the buildings you'd designed."

He transferred to the National Capital Housing Authority in 1939 and can still see today the "thousands and thousands" of apartments he helped design to house war workers here. By 1944 he had a Navy commission and was sent to the South Pacific with a military government unit, where his engineering skills were called upon to design army camps and things like large latrines for troops and civilians on a devastated Okinawa.

Hansen set up his own practice in Silver Spring after a brief filing with a large architectural firm here. By itself, the list of local churches whose structures he has designed would fill a church registry - among them St. John's, St. Jude's, St. Camilla's, St. Stephen's, St. Catherine's and several St. Mary's. He has similarly been a consultant or engineer on dozens of Washington embassy buildings, schools and office buildings and been an expert witness almost monthly in civil suits over building damage, such as that caused by Metro construction.

He has done the structural designs for the restoration of Alexandria's Lyceum and historic buildings like Decatur House and City Tavern in Georgetown and has till found time between this and engineering rescue missions abroad to be active in engineering societies and even time to be a judge at local high school science fairs.

John Bachner, executive director of the Consulting Engineer Council of Metropolitan Washington, of which Hansen is a past president, said "Carl's one of the most active and interested of our members. He's never turned down an assignment no matter how busy he is. He's a technically competent, highly concerned man of great personal ethics, a model of the profession," Bachner said.

Hansen's not always been the bearer of glad tidings. Not long after RFK Stadium was built, its three miles of concrete walkways began crumbling and Hansen was called in to diagnose the problem (aluminum electrical conduits "corroding because of galvanic action between the aluminum and steel rods in the concrete").

Hansen was a consultant to the American Institute of Architects in the 1960s when it pleaded with Congress to preserve and restore the historic west front of the U.S. Capitol rather than build a new west wing, a proposal that Congress is still considering.

Hansen surveyed the west wall and found it structurally sound despite warnings of then Architect of the Capitol J. George Stewart that it might collapse at any moment if a helicopter flew nearby. Stewart, who successfully pushed for the Capitol's new east wing during the 1950s, wanted a new west wing to create more office space.

"A New York engineering firm also told them later that it could be restored," said Hansen "and tha tbomb that went off (near the Rotunda in 1971) didn't budge the wall an inch. But Stewart wanted an extension and now George White (Stewart's successor) leans toward an extension too. It's tragic; this last, only original part of the building left should be preserved for posterity. But all everybody seems to be concerned about is a little extra office space."

It's something Hansen, with perhaps a few Seabees, would like to have a crack at.