A New York–bound Amtrak train derailed in Philadelphia last night, leaving at least six passengers dead and more than 200 injured. Department of Transportation and National Transportation Safety Board officials are investigating the reason for the accident, which is sure to be a flashpoint in an ongoing battle to upgrade the nation’s infrastructure.

The debate resumes today: The House Appropriations committee already had plans to mark up a bill on Wednesday that would, among other things, cut funding to Amtrak from $1.4 billion to $1.14 billion. (Britain, for the record, spends $8 billion annually on its rail network.) Not all Republicans are on board with the cuts. Pennsylvania Rep. Ryan Costello, who sits on the House Transportation and Infrastructure Committee, on Wednesday promised he's "not in that camp" and “if that bill shows a reduction when it hits the floor, myself and others, I think you’re going to see amendments to make sure that there is stable funding on the northeast corridor.”

President Richard Nixon created Amtrak in 1970 to boost passenger rail service, but he made it a for-profit corporation. That's the cause of many its political troubles today. Amtrak has never been able to turn a profit, and Republicans—who favor a fully privatized rail system—are loath to spend taxpayer dollars on a money-losing operations. They have repeatedly threatened to slash federal funding for Amtrak, which has struggled to make do with what Congress gives it. In an annual report to Congress from February, Amtrak President Joseph Boardman described “critical infrastructure stressed to the breaking-point” that result in “frequent service meltdowns”: “Efforts by Amtrak, the freight railroad industry, and state and local governments to address these problems are thwarted by the lack of adequate and reliable Federal funding to match state and local investments in rail, and to attract private investment capital and facilitate public-private partnerships.”

And yet, rail safety has improved in the last decade. The Huffington Post notes that accidents in 2014 were down 42 percent since 2006. Meanwhile, Amtrak ridership on the Northeast corridor from Boston to Washington, D.C., hit an all-time high in 2014. Amtrak accounts for over three-fourths of air and rail travel between Washington and New York, and two congressman happened to be on the same train last night: Sen. Tom Carper of Delaware, who got off shortly before the derailment, and former Congressman Patrick Murphy, who was on it. Boardman says even the popular Northeast corridor is starved "of the vital capital necessary to maintain and expand upon that success."

A 2013 report from the American Society of Civil Engineers gives the state of U.S. rail infrastructure a C+, slightly higher than the infrastructure grade for the nation as a whole (D+). By 2040, Amtrak expects traffic in the congested Northeast corridor to quadruple today’s ridership. "To meet future demand in the Northeast Corridor for both Amtrak and the eight commuter railroads that use the corridor, estimated investments are about $10 billion over the next 15 years to achieve a state of good repair and to increase train capacity by 40%," ASCE writes. "Maintaining adequate track capacity to address expanding passenger and freight needs is among the largest challenges in creating a competitive passenger railroad network."