THE FIRST TIME a chunk of concrete from the scarred and pockmarked 86-year-old 25th Street Bridge in South Philadelphia rained down on Ed Penna's car and cracked his windshield, he sent the repair bill to CSX Corp., the Florida-based transportation giant that owns the lengthy overpass and controls most rail freight on the East Coast.

He said CSX laughed that off.

So the second time it happened, the labor leader just went ahead and paid for it. And the third time.

Now, after about a dozen years working in the shadows of the crumbling overpass in the Ironworkers Local 405 hall at 25th and Reed, he's almost gotten used to it - that clanking sound and the way the whole building shakes when a 100-car train hits the brakes overhead. And his fear that a concrete slab might kill a pedestrian one day.

"Actually in the winter it's probably worse," said Penna, speaking from the safety of his office. "You can see the ice that forms there, and it literally breaks chunks of concrete down and it falls in the street."

But this winter, things are different along 25th Street. A sudden spike in freight traffic because of the surge in North Dakota oil production and the reopening of South Philly's massive refinery, a nearly disastrous derailment on the 128-year-old bridge over the Schuylkill River, and news coverage of a nearly 30-foot concrete slab falling have raised fears. But there's also hope that CSX will finally address Philadelphia's infrastructure crisis.

On Wednesday, executives from the notoriously tight-lipped freight line are slated to arrive from Jacksonville, Fla., to testify at a City Council hearing on freight-rail safety. It's suddenly a front-burner issue after two oil-laden tanker cars nearly tumbled from the circa-1886 Schuylkill Arsenal Bridge and a spate of oil-by-rail accidents elsewhere, including one in Quebec that killed 47 people in July.

Councilman Kenyatta Johnson - whose district is bisected by the milelong oil trains that arrive about twice a day from North Dakota - said he's optimistic that CSX will announce stepped-up maintenance and an infrastructure overhaul that will address safety concerns that have festered in South Philly, Grays Ferry and other parts of the city for decades.

"Their participation in this hearing, sending actual representatives from Florida, and their admission about repair and maintenance that needs to be done on their rail properties gives me some hope that going forward we will have a better time getting CSX to respond to my concerns and the concerns of the people of Philadelphia," Johnson said in an email to the Daily News.

The upcoming hearing at City Hall - a joint meeting of Council committees on Transportation and Public Utility, and Public Safety - comes just as shipments of tanker cars containing crude oil are on the brink of flooding the region.

The iconic former Sunoco refinery in South Philly reopened last year as Philadelphia Energy Solutions and now ships about 5 million barrels of crude from North Dakota's Bakken field through the core of the city every month.

In addition, a new facility to accept oil by rail and transfer it to barges on the Delaware River is slated to open in Eddystone this month, and work is beginning across the river in Paulsboro, N.J., to convert a former asphalt refinery to handle oil-tanker cars.

When Geronimo gave up

Meanwhile, the run of accidents - punctuated by the Jan. 20 mishap on the Schuylkill Arsenal Bridge, which CSX later blamed on shoddy repair work by its own crew that failed to properly refasten ties - has made people realize that only the federal government has jurisdiction over whether the lines are safe. But government inspections are rare and critical safety information about bridges like the Schuylkill crossing - built during the first presidency of Grover Cleveland, in the year that Native American chief Geronimo surrendered - is not public.

Ian Savage, a Northwestern University economist and expert on rail safety, notes that before 1970, there wasn't even federal safety oversight of the freight lines - a situation that changed with shoddy maintenance before bankruptcies like Philadelphia-based Penn Central. Today, the rail-cargo business is booming - CSX took in $12 billion last year, and posted a $3.5 billion profit - but the surge in oil transport, and growing evidence that the oil fracked from North Dakota is more prone to fire and explosions, has raised new infrastructure concerns.

"It's very debatable whether the deployment of federal track inspectors since 1970 has had any measurable impact on track quality," Savage acknowledged. A Government Accountability Office study in 2007 found inspections proceeding at a rate that would take 500 years to cover all the nation's freight lines, and the railroads have used concerns over competition and liability to keep most safety information away from the public.

Few of the 140,000 miles of freight rail in America are quite like the 25th Street elevated line, finished in an art-deco style by the then-Pennsylvania Railroad in 1928, right before the Great Depression hit. Extending from the east end of the Schuylkill Armory Bridge in Grays Ferry all the way to the Navy Yard, the overpass - wide enough for four tracks, although currently with just two operating - has exasperated residents for years.

"That structure would not be allowed to exist anywhere else in the city unless it were federal," said Doug Rahm, a mason who has lived and worked along the 25th Street corridor for many years. "It is so dangerous that I will not drive underneath it."

Rahm has taken dozens of photos of sections of the overpass that he believes are unsafe, and he's complained frequently over the years to city officials who've responded that there is little they can do.

Decay for all to see

You don't need to be a mason or an ironworker to visit 25th Street and see the signs of eight decades of unrelenting entropy: the bare patches where concrete has slid off, or entire sidewalls that have vanished to be replaced by tin fencing, where a graffiti vandal has scrawled the word "Bad."

In response to the spate of accidents in 2013, the railroad industry announced a series of voluntary steps, including slower speeds in large cities (although it wasn't clear whether that would affect Philadelphia, where officials said the top speed was already just 30 mph).

CSX, which responded to inquiries with a lengthy email statement, said the company is eager to work with the federal government, local authorities and other parties on what it called "a measured approach" to enhancing crude-oil transportation, including strengthening the current generation of tanker cars that safety experts have cited as flawed. Said the railroad: "CSX places the highest priority on the safety of the communities in which it operates over its 23-state, 21,000-route-mile network, including Philadelphia."

But local elected officials like Councilman Johnson are hoping for more. He said he's concerned about other issues such as trash dumping along the CSX lines, and whether the rail company is ignoring poorer neighborhoods.

"It puzzles me how a company [that] makes $12 billion . . . last year hasn't addressed longstanding issues that threaten real people, yet they can do a massive update to the lines along the Schuylkill trail" in Center City, he said. "I'm concerned about where the priority is being placed, and why."