Serge Nalbantian is hardly a household name. But in Philadelphia, he has helped make quite a sizable impression - as in the soaring 975-foot Comcast Center.

Nalbantian was one of four development managers for Liberty Property Trust on the $500 million tower of glass that officially opened in June.

With its super-high-definition video wall in the lobby and the shopping concourse below - Nalbantian's primary areas of responsibility - it has become as much tourist attraction as office building.

Yet Nalbantian is a casualty in the ongoing economic horror show that has no apparent end and that has brought the development industry largely to a standstill. He has been laid off.

While his job loss has rattled colleagues, the Lower Merion resident chose today not to talk about it.

The latest sobering measure of the breadth of the employment carnage comes tomorrow when the U.S. Labor Department releases job data for November. Forecasters are predicting close to 300,000 job losses, possibly more - up from 240,000 in October.

If this week is any harbinger, December's report won't be any cheerier. At least 29,772 job cuts have been announced by companies around the country since Monday. That's enough people to fill all the seats at the Wachovia Center - with an additional 8,000 left standing.

The Labor Department said today that while new claims for jobless benefits were down last week, the number of people claiming benefits - 4,087,000 - reached a 26-year high.

"Those big numbers are very, very frightening," said Rich Stein, research director at the Economy League of Greater Philadelphia.

The hits came one after the other today.

AT&T Inc., based in Dallas, said it intended to cut 12,000 jobs, or 4 percent of its workforce.

By the afternoon, the entertainment industry announced its own round of shedding. Viacom Inc., the parent of MTV Networks, disclosed that its workforce was lighter by 850 positions, or 7 percent. NBC Universal Inc. revealed plans to eliminate 500 jobs, or 3 percent of General Electric Co.'s entertainment division.

Closer to home, DuPont Co., based in Wilmington, disclosed plans to eliminate 2,500 positions, most of those serving the U.S. and European automotive and construction markets. The chemical manufacturer cited the steep decline in home building, auto sales and consumer spending.

DuPont also said it would let loose 4,000 contractors by the end of this year, with more reductions expected in 2009.

That followed an equally dismal Tuesday and yesterday, when:

The international law firm of Reed Smith L.L.P., whose headquarters is in Pittsburgh, with offices in Philadelphia, told employees that 115 support positions had been cut throughout its U.S. offices.

Electronics retailer Tweeter Home Entertainment Group Inc. converted its bankruptcy case to Chapter 7 liquidation, closed its 70 stores, and fired more than 600 employees.

Little-known Hoeganaes Corp., a Cinnaminson manufacturer of metals used in auto parts, announced its intentions to put an end to its manufacturing activity in February and to lay off its last seven plant employees, leaving about 70 employees in research and development and in headquarters functions.

Not that Monday was a day of solace. That was when official word came that the United States was in a recession and had been since December 2007. As if to underscore that fact, JPMorgan Chase & Co. announced a plan that day to shed 9,200 jobs at Washington Mutual Inc., which it acquired in September.

At Temple University, David Elesh, a sociology professor, said even small layoffs merited notice because of their cumulative effect.

"It's the continuing chorus of such announcements that has such an impact," he said, predicting an increasingly fearful employed public.

The fear, Elesh said, is "of not being able to provide for one's family."

That will result in a greater decline in consumer spending, which, in turn, will lead to more layoffs, he said.

"This kind of negative news makes people fearful for their own jobs, and they are more inclined to save," Elesh said. "As they save, more companies will face declining sales and profits."

In such an environment, not even the most-talented are secure. Nalbantian is evidence of that, said John Gattuso, senior vice president and urban regional director for Liberty Property Trust. He let Nalbantian go in late October.

"The downside of particularly large projects is it's difficult to maintain 100 percent of that workforce on an ongoing basis without projects moving in to replace them," Gattuso said. From a staff of 500, Liberty has laid off four, a spokeswoman said.

Layoffs have hit a number of the region's developers. At Westrum Development Co., of Fort Washington, the workforce has shrunk from 82 people last December to 25.

"We are doing what's called cocooning," chief executive officer John Westrum said recently.

At Liberty Property Trust, Gattuso said the mantra was "batten down the hatches."

"We, like other companies, are trying to make sure we have ourselves positioned to get through this," he said, "and thrive on the other side."

Contact staff writer Diane Mastrull at 215-854-2466 or dmastrull@phillynews.com.

Staff writer Roslyn Rudolph contributed to this article.