As the eye of Hurricane Katrina passed over New Orleans during the morning of Aug. 29, officials had closed all major routes, including the 32-mile causeway and the twin spans of Interstate 10 across Lake Ponchartrain, says a Louisiana Dept. of Transportation and Development. Reports of 4-ft-high flooding on U.S. 90 and 3 ft of flooding in some canals were expected, says Mark Lambert, LADOTD spokesman, speaking by cell phone and without electricity. "The storm is at this moment getting closer," he said at about 10:30 a.m. "It's very hard to assess anything right now."

While most of the highways are built to withstand major hurricanes, the possibility of flying debris causing damage is a big concern, and several old moveable bridges may be at risk, he adds. The biggest transportation item of concern right now is an old nine-mile connector of LA 1 to Port Fourchon. The connector carries 18% of the nation's oil and gas supply. Moreover, the connector links to Grand Isle's Barrier Island, which is inhabited. "We are almost certain that the whole connector may be underwater," says Lambert. Ironically, the LADOTD was in the middle of conducting a report to investigate why two bids this July to replace—and elevate—the connector came in $100 million over engineers' estimate of $154 million (ENR 7/18, p. 13).  The new connector would be 22.5 ft high.

Winds, estimated at 150 miles per hour, ripped two holes in the roof of the Superdome early Monday. By midday, ground-level witnesses counted up to 60 gaps in the ceiling. The vast structure, with 77,000 seats, is New Orleans' main storm shelter, currently home to 8,000 to 9,000 residents who were unable or unwilling to heed the mandatory evacuation order.

An engineer who inspected the roof at the request of Gov. Kathleen Blanco (D) declared it sound, according to news reports.

Strips of metal began peeling away from the roof early on the morning of Aug. 29, and numerous other leaks were reported as well. But damage appears to be limited so far to the roofing material.

Designed by Curtis and Davis Architects and Planners and built in 1973 by Huber Hunt and Nichols, now part of Phoenix-based Hunt Group, the Superdome was roofed with steel framing covered with polyurethane. The roof's sprayed-on Hypalon membrane was damaged in 1980 by a freak hailstorm. By the time a decision was made to proceed with repair, the original estimate of $450,000 had ballooned to $4.5 million, in part because of subsequent corrosion of the steel members (ENR 8/5/82 p. 11).

The state and the building's insurer, Reliance Insurance Co., Philadelphia, reached a settlement in 1987 for $2.7 million to repair the roof (ENR 2/12/87 p. 16). An architectural firm that recently studied the Superdome's interior, but not its roof, says that the roof may have been replaced two or three years ago.

The U.S. Army Corps of Engineers New Orleans District instructed its personnel to evacuate the city on Saturday. Many of the 1,500 employees headed for the Corps Mississippi Valley headquarters in Vicksburg, Miss. On Monday morning the Corps was establishing a hurricane command center there and coordinating recovery operations and monitoring operations of the Mississippi River levee system. Water was overtopping the Industrial Canal lock walls on the East Bank of the city, reported John Hall, Corps public affairs officer, "But so far the structure is holding," he said.

The Industrial Canal Lock, which spills water from Lake Ponchartrain when necessary, is one of the busiest in the world. The busy trade link connects the Mississippi River, the Gulf Intracoastal Waterway, the Mississippi River-Gulf Outlet, the Inner Harbor Navigation Canal and Lake Ponchartrain. Congestion is common; barge strings often wait up to 36 hours to pass through the lock, which measures...