Massachusetts' attorney general is demanding that contractors refund $108 million for poor work on Boston's "Big Dig," which is the biggest public works project in U.S. history and has been plagued by leaks and delays. Attorney General Tom Reilly's office plans to sue Bechtel/Parsons Brinckerhoff and other companies if the two sides do not reach an agreement over some 200 complaints of shoddy work in putting a major highway running through downtown Boston underground... Costs for building the 7.8 mile underground roadway through Boston ballooned from under $3 billion to the current $14.6 billion.