WASHINGTON Members of the National Transportation Safety Board and other federal officials are calling for the nations bridge inspection process to change following the release of an NTSB report that cited design flaws and inadequate load capacity as contributing to the collapse of the I-35 bridge in Minneapolis in August 2007.

The collapse killed 13 people and injured 145 during the evening rush hour on Aug. 1, 2007.

The NTSB issued its final report on the collapse here last month, declaring that a design flaw during previous modifications, plus the weight and placement of construction equipment, created a perfect storm that led to the collapse of the Interstate 35 span.

"We believe this thorough investigation should put to rest any speculation as to the root cause of this terrible accident and provide a roadmap for improvements to prevent future tragedies," said NTSB Acting Chairman Mark V. Rosenker.

U.S. Rep. James Oberstar, D-Minn., who chairs the House Transportation and Infrastructure Committee, said bridge inspectors now will have to expand their work, going back to the design of the bridge itself and reviewing the engineering documents.

"They can no longer assume that the bridge was properly designed," said Oberstar.

NTSB officials said the inadequate design of the bridges gusset plates, while the responsibility of the designing firm, were not detected by state or federal transportation officials in previous reviews of the 40-year-old I-35W bridge.

Oberstar said there are 740 bridges of similar age and design in the U.S.

Oberstar filed a bill in the U.S. House following the bridge collapse, calling for the federal government to spend $1 billion and revise the way structurally deficient bridges are prioritized for repair or replacement.

The bill passed the House overwhelmingly but was stalled in the Senate prior to the recent federal election.

Congress and the Obama Administration will have the task of addressing the nations aging highway and bridge infrastructure as committees, including Oberstars, set out to write the next large-scale highway and public transportation bill due in Congress next year.

Meantime, U.S. Transportation Secretary Mary Peters directed the Federal Highway Administration to revise its training materials and inspection procedures and to work with the states to improve the design process.

"All of us in the business of transportation safety have an absolute responsibility to ensure that the right lessons and the right conclusions are drawn from this terrible incident," Peters said.