Since the U.S. government shutdown started, one-fourth of MicroTechnologies LLC's workforce of 400 in Vienna, Virginia, has stayed home. The headquarters is like a "ghost town," Chief Executive Officer Tony Jimenez said.

"I've seen more people cry in the last couple of days than the last few years," Jimenez said in a phone interview yesterday, after six federal agencies he wouldn't identify told the company to stop work on contracts. "You don't take people's jobs and play Russian Roulette with them."

The partial shutdown that began Oct. 1 is beginning to have a ripple effect on federal contractors, which employ millions of people and attract more than $500 billion in annual awards. Costs will rise each day that government offices remain closed. The defense industry, the single biggest recipient of contracts, will likely be the hardest hit.