For 15 people, trains speeding along the city's railroads have been a gruesome, but easily accessible, means of killing themselves over the past five years.
At least three people have committed suicide on Philly train tracks so far this year. There were five in 2010, four in 2009, one in 2008 and two in 2007, according to the Philadelphia Medical Examiner's Office.
During the same time span, 10 people have killed themselves on railroad tracks in Montgomery County, according to Walter Hofman, the county coroner.
As of Sept. 1, four people have committed suicide on Montco railroads this year - up from two in 2010 and zero in 2009, Hofman said.
He said that suicides, and suicides by train, appear to be occurring more frequently.
A 52-year-old Harleysville man was hit by a SEPTA train in Lansdale on July 29. Officials said that an engineer had blown the horn but that the man never moved.
A 22-year-old Langhorne man committed suicide on the tracks of the SEPTA West Trenton line on July 22.
A 29-year-old woman was killed by a SEPTA train on the Warminster Line on June 20, after officials said that she had lain down on the track in Hatboro.
Last year, two teenage girls died when they jumped in front of a speeding Amtrak Acela train near Norwood station in Delaware County.
For railroad engineers who see a suicide or fatal accident, the memories are nearly impossible to overcome.
Some shrug the incidents off as a grisly rite of passage; others are so shaken, they can't return to work, engineers say.
They often rely on each other for support afterward.
It is not like a car accident. After the emergency brakes take hold on a speeding train, the engineer and conductor brace for the unthinkable while the figure of a person on the tracks comes into clear, horrific view.
Time seems to stand still as rail workers desperately hope that the person in the path of their roughly 400-ton locomotive will move out of the way.
"It's like everything is in slo-mo," said John Tolman, vice president of the Brotherhood of Locomotive Engineers and Trainmen. "What you go into is like a tunnel vision. You're, like, so blown away - you just feel horrible."
It can take up to a mile for a train to grind to a stop. Stopping distance depends on speed, weather and track conditions, and whether the train is at capacity, or moving downhill.
The violent end of one person's suffering typically marks the beginning of anguish for many others.
Engineers and conductors who watch, and hear, someone crushed under their train can face post-traumatic stress disorder, although it may manifest itself differently in different people.
"Some of them never get over it; some of them never get back into running trains," Tolman said, adding that a suicidal person making eye contact with an engineer before they are run over can be a particularly chilling experience.
Dixon, general chairman for the local chapter of the Brotherhood of Locomotive Engineers and Trainmen, tells other engineers never to look at the disfigured body of someone who's been hit by the train they're operating.
"You already saw them in one condition," he said, "You don't want to see them afterwards."
Many railroads offer employees who witness critical incidents, like suicides, counseling through employee-assistance programs, although there is not a federal mandate to do so.
After the teenager dived in front of Dixon's train years ago, Dixon sought help from a counselor through the company's employee-assistance program.
"For about two or three days I kept trying to figure out why," he said, referring to the boy's reasons for committing suicide.
Although the initial reaction to witnessing a suicide on the tracks can be visceral and emotionally crippling, Dixon said that most engineers are told early in their careers that suicides happen and that there is essentially nothing anyone can do to prepare for it.
"You still have a job to do; you have to get back in there and do it," he said. "You can't take the blame for it - you have no control over it."
The Federal Railroad Administration, based in Washington, D.C., is working to determine what can be done to prevent the incidents.
Until three months ago, rail companies were not required to report suicide fatalities to the FRA under accident-disclosure guidelines.
As a result, there is no way to know if suicides by train are occurring more or less frequently on a national level.
"Because suicides are deliberate acts over which train crews effectively have no control, train crews reported such events [only] to their employer - as required under operating rules - and to local authorities," FRA spokesman Warren Flatau said.
He said that regulations, which went into effect June 1, were upgraded so that his agency could determine what preventive measures might be effective.
FRA officials estimate that 40 percent of about 500 yearly trespasser fatalities nationwide may be suicides.
Suicides are up
Data complied by the Centers for Disease Control and Prevention showed that suicides of all kinds rose 2.7 percent nationwide from 2007 to 2008. There were 35,933 confirmed suicides in '08 - roughly 98 per day - which is the most current data available.
Hofman said the statistics are a cause for concern, but aren't necessarily a surprise.
Suicides in Montgomery County have risen by about 24 percent since 2008, he said, adding that economic woes have clear implications on regional and national suicide rates.
"The same thing happened during the Great Depression people dove in front of trains, jumped out of buildings," Hofman said.
Officials at the FRA said that rail-related suicide rates could also be underestimated because coroners and medical examiners in some places may not list suicide as a cause of death.
The FRA is wrapping up a four-year study on rail-related suicides, and plans to release the findings at the end of the year, Flatau said.
The American Association of Suicidology is working with the FRA, using psychological autopsies to try to determine a person's lifestyle and state of mind before committing suicide.
Reviewing personal records and conducting interviews with close friends and relatives can reveal reasons why someone may have committed suicide, such as depression, and why the person chose to do so by being hit by a train.
Hofman said that many people who commit suicide this way have tried killing themselves by other means and failed.
Open access to railroad tracks also presents opportunities.
"One of the reasons is simply because of the general accessibility and availability of this, a highly lethal method," said Alan Berman, executive director of the American Association of Suicidology.
"The goal of the study was to learn as much as possible to inform potential prevention programs," he said. "The goal is to reduce the number and impact of these events."
Despite the attention that the issue is getting from federal agencies and suicide-prevention networks, railroad employees are unsure what can be done to prevent people from diving in front of trains.
"To try to prevent someone from hurting themselves, when our system is intended to be accessible to everyone, is a difficult process," said Scott Sauer, manager of operational safety at SEPTA. "We try to protect people from themselves."
The transit agency has considered posting phone numbers to local help lines near their tracks, but Sauer said that there is no proof of that being an effective means of prevention elsewhere.
Says engineer Dixon: "I don't know if there is anything that can be done. People are gonna do what people are gonna do."