The work is tough, the risks are many, and the margins can be thin, but a few have made major fortunes in the construction industry, as the 24th Annual Forbes Magazine list of the 400 Richest Americans shows. Topping the list from the construction industry is Dennis Washington, chairman of Washington Group International, Boise, Idaho. Forbes estimates his fortune at $2.5 billion.

Dennis Washington (Photo by Michael Goodman for ENR )

Right behind are Chairman Emeritus Stephen Bechtel Jr. and his son Riley Bechtel, current chairman and CEO of engineering-constructor The Bechtel Group, San Francisco. Forbes estimates their fortunes at $2.4 billion each

No. 164 on the Forbes list, worth $1.8 billion, is William J. Pulte, founder of Bloomfield Hills, Mich.-based homebuilder Pulte Homes. Walter Scott Jr., former CEO and now chairman emeritus of contractor Peter Kiewit Sons�, Omaha, came in at No. 198 on the list. He has an estimated fortune of $1.6 billion.

Two more homebuilders round out the list. Donald R. Horton of Fort Worth, Texas, ranked No. 235 with an estimated fortune of $1.4 billion, and Miami-based residential developer/builder Jorge M. Perez of Related Group of Florida came in at No. 283 with a fortune of $1.2 billion.