WASHINGTON -- A section of track under scrutiny in the crash of an Amtrak passenger train that killed one person and injured 96 others in Iowa was installed last month and may have been defective, the railroad's chief executive said on Wednesday.

Citing preliminary evidence, Amtrak President and CEO George Warrington told a congressional hearing it appeared the new track broke when the California Zephyr from Chicago rolled over it late Saturday night, according to a wire service.

Both engines and 11 cars of the westbound train from Chicago derailed in southwest Iowa.

Warrington stressed to lawmakers his information only suggested a possible cause and that the National Transportation Safety Board, which is investigating the crash, would have the final say on what happened.

The tracks along the route are inspected regularly by track owner Burlington Northern Santa Fe Corp. (NYSE:BNI - news), and Warrington said an inspection in mid-February turned up a defective section of track.

"And as they should have, they replaced that section of track," Warrington said.

"There is not a final conclusion, but I believe the preliminary evidence suggests that section of track that had been installed had some sort of manufacturing or internal defect," Warrington said. "It appears that way and under the lateral forces of our train it broke.

"If a rolled piece of steel rail has in the manufacturing process a defect, it will fail," he said. "It appears that's what happened in that situation."

The safety board has removed the mangled section of track for study.

In addition to Amtrak trains, the tracks are used by freight trains, many carrying coal. Amtrak has resumed service on the line.

Despite the crash, Transportation Department Inspector General Kenneth Mead told the hearing in the House of Representatives that Amtrak has a good safety record, especially on its Northeast Corridor route, which it mostly owns and operates.

Outside of the Boston-to-Washington route, Amtrak operates nearly all of its services over tracks owned and maintained by major freight railroads.

The appropriations subcommittee hearing was on Amtrak's finances, which are under scrutiny as it struggles to become operational self-sufficient by fiscal 2003.