A series of missteps and oversights by the companies excavating a tunnel at Dulles International Airport contributed to a November cave-in that killed a 50-year-old construction worker, the Virginia Department of Labor and Industry said yesterday.

In the week before the tunnel gave way, there were three partial collapses, each increasing in severity, state inspectors alleged in citations issued yesterday. They found that an engineer working for Kiewit Construction Co. who was supposed to assess the tunnel's stability daily hadn't visited the site during the month leading up to the collapse.

State inspectors also determined that Kiewit had tunneled under a rainwater catch basin without checking whether the soil was stable.

But the Omaha-based company continued to send workers inside, the report said, including Robert E. Parson Jr., of Spotsylvania County. Rescuers dug through the rubble by hand for more than 24 hours during a search for Parson. His body was recovered five days later.

Parson's widow, Theresa Parson, began crying when she learned of the state's findings. Her husband had worked on Kiewit crews for more than 30 years. "It's very, very shocking," she said. "I don't see how they could put someone's life in danger."

Kiewit was penalized for two safety violations with fines totaling $77,000. Two citations carrying a total of $32,000 in fines were issued to Parsons Management Consultants, the District-based firm overseeing the expansion of the airport. The companies have 15 business days to decide whether they will contest the findings.

Kiewit spokesman Jerry Pfeffer declined to comment yesterday on the specific allegations but maintained that the company had "complied with all applicable safety and health requirements." He added in a written statement that the company had not completed an internal review.

"We are extremely disappointed that any citations were issued, and we strongly disagree with the department's allegations," Pfeffer said in the statement. "We intend to further address these allegations with the department and, if necessary, contest them."

Leslie Pereira, a spokeswoman for Parsons, said yesterday that the company had not received the citations and declined to comment.

State officials also declined to comment on their report.

The 770-foot tunnel was being excavated for a moving walkway that is part of $3.4 billion expansion at the fast-growing airport. The project includes a new terminal, a fourth runway, thousands of parking spots and a subway system to replace the mobile lounges now used to shuttle passengers between the main and midfield terminals.

Parson was one of four workers in the tunnel when it collapsed Nov. 1, just days before the excavation was expected to be completed. The others escaped the crush of rock and red clay.

Rescuers worked around-the-clock after the collapse, painstakingly removing the earth by hand. They gave up the search after about 24 hours, deciding that Parson could not have survived the cave-in and that further rescue attempts were too risky.

In the citations, state inspectors said that Kiewit had deviated from the building specifications in the contract, creating a situation in which sections of the tunnel were "lacking full support and stabilization."

As the work continued, "ground conditions deteriorated," the report says. On Oct. 24, 25 and 31, "falloffs" were reported in the tunnel. During the first incident, one cubic yard of dirt fell; the next day, four cubic yards fell; in the third incident -- the day before the cave-in -- five cubic yards fell. According to the report, there had been 10 falloffs at the site in the six months before the collapse.

State inspectors said the engineer who should have had daily discussions with Parsons about the ground conditions and was responsible for ensuring that the excavation was safe was not on site in October and was not notified. The engineer had been there for "only a brief portion" of September, inspectors said.

Tara Hamilton, a spokeswoman for the Metropolitan Washington Airports Authority, said in a written statement: "Our safety record is strong; however, this tragic accident has made us even more committed to safety in our current and future construction projects."

The expansion is slated for completion in 2003.