A Burlington Northern & Santa Fe freight train passes cars from from an Amtrak train that derailed late Saturday night. Union officials are raising questions about safety on the BNSF Railroad.

NODAWAY, Iowa -- Two union officials raised questions Tuesday about general safety and maintenance on the Burlington Northern Santa Fe Railroad following a fatal Amtrak train derailment Saturday on Burlington tracks near Nodaway, Iowa, the Omaha World-Herald reports.

Federal officials are targeting a broken 16-foot temporary rail patch as the possible cause of the derailment, which killed one person and injured more than 90, three of them seriously. Burlington Northern had installed the rail patch within the past month.

Raising concerns were officers of the United Transportation Union, whose members work as conductors and in other operating jobs, and the Brotherhood of Maintenance of Way Employees, whose members inspect and repair the rail lines -- who maintain the "way" for railroads.

"We have had a tremendous reduction in the number of maintenance of way forces, not only in that area but across the whole BNSF," said Dave Joynt of Hastings, Neb., general chairman for Maintenance of Way members who work for Burlington Northern in Iowa, Nebraska and several other Midwestern and Western states.

He said 600 to 700 of the union's members in his region have been furloughed by the railroad, although thousands remain on the job.

"The railroads aren't doing so great," Joynt said. "Their stock's been down. They have made their reductions for economy reasons. ... They've cut some of the core section people who maintain these (rail) corridors throughout the winter."

Byron A. Boyd Jr. of Cleveland, president of the transportation union, sent a letter to Burlington Northern officials proposing a safety summit that would allow discussion of "a full range of issues related to safe rail operations and working conditions."

The union's letter, dated two days before the Amtrak wreck, said that a March 3 switching accident near Willmar, Minn., had killed a Burlington Northern conductor.

Also in the letter, Edward Dubroski, president of the Brotherhood of Locomotive Engineers International union, said, "We share President Boyd's concern about safety on the BNSF." Dubroski called safety efforts on the railroad "disappointing."

Ted Turpin, who is heading the National Transportation Safety Board investigation into the Amtrak derailment, said officials are trying to determine whether the temporary piece of rail line caused the accident or whether it broke during the derailment.

He said the rail break occurred in a location where Burlington Northern had recently repaired the track because the old rail had a defect.

"They had replaced the little section of defective rail with another piece of rail, and that new piece was the rail that broke," Turpin said. "It was intended to be repaired again because it was only a temporary fix."

Burlington Northern spokesman Pat Hiatte of Fort Worth, Texas, said the railroad had been discussing the idea of a general safety meeting with the unions for some time and certainly would agree to meet.

He said there was no reason to believe from Saturday's derailment that there are safety problems with the main BNSF line across southern Iowa, which handles extensive freight traffic as well as Amtrak trains. The derailed train had 241 passengers and a 16-member Amtrak crew and used 11 passenger cars pulled by two Amtrak locomotives.

"We're concerned about safety, always are," Hiatte said, "and always looking for dialogue with any responsible group ... to discuss with any group the possibilities and the options for safety improvement."

Hiatte said railroads have been able to reduce their employment of track maintenance workers by using better road-building materials and improving testing and maintenance equipment.

According to Federal Railroad Administration records, Burlington Northern reported 50 train accidents from 1981 through 2000 in four southwest Iowa counties, citing track problems as the cause in 20 of them.

The accidents killed one person, injured eight and caused $10.4 million in damage, according to the records of accidents in Adams, Mills, Montgomery and Union Counties.

Hiatte, the Burlington Northern spokesman, said he didn't know whether the report indicates an unusual number of accidents. The southern Iowa route is a high-traffic line, he said, and high traffic raises the possibility of accidents.

For the railroad as a whole, he said, Burlington Northern's accident rate has improved. For rail equipment accidents and incidents -- excluding rail-crossing accidents -- per 1 million miles, the railroad had 4.16 accidents in 1995 and 3.43 accidents in 2000.

He didn't have accident rates for the southern Iowa route but said preliminary findings regarding two recent freight train derailments, also along the railroad's southwest Iowa line, indicate no consistent pattern of accident causes.

Fifteen cars on a freight train derailed near Stanton, Iowa, on Dec. 13, apparently because a welded piece of a switch failed, causing a train wheel to go off the track and derailing the cars, Hiatte said.

On New Year's Eve, part of a coal train derailed near Red Oak, Iowa, apparently because an overheated wheel bearing caused the wheel to fail and a coal car to drop down onto the road bed, he said.