The death toll from Monday's terrible rail accident in Washington, D.C., hasn't yet been verified, but early estimates put it at nine people, with scores of others injured.
While rescuers continue to search the wreckage for survivors, investigators from both Washington's Metro and the National Transportation Safety Board have begun their investigations into the deadliest train wreck in D.C. history.
Months may pass before we know exactly what caused one train on the Metro's Red Line to slam into the back of another, jackknifing on top of it. Early speculation holds that the operator never hit the brake before slamming into the train in front.
When investigators find out more, this week's crash will join other crashes scattered through the years that taught train operators valuable safety lessons.
1. Paris, 1903
The Crash: By the official count, 84 people died in the Couronnes Disaster, a tragic rail fire in turn-of-the century Paris. After the train caught fire, many passengers tried to flee, but found no escape from the tunnel.
Here's the original New York Times story on the disaster, which reported that 100 were dead, "Suffocated in Tunnel by Smoke From Burning Train."
The Lesson: Transit historian Brian Cudahy, who wrote about the disaster in "A Century of Subways," tells Popular Mechanics that that the French disaster led companies to adopt some of the fire-safety procedures we're familiar with today. Most notably, it established the idea that fire exits should be available and marked.
2. Brooklyn, 1918
The Crash: Multiple factors conspired to make Nov. 1, 1918, a dangerous day to ride a train in New York City. A union of locomotive engineers had just gone on strike, pressing an inexperienced motorman into service. And the tunnel on Malbone St. in Brooklyn had just opened.
That day, operator Edward Luciano took a tight corner at more than 30 miles per hour, wrecking the train. Cudahy wrote an entire book about the disaster. In his research he confirmed 93 fatalities, though other sources claim as many as 103.
The Lesson: Cudahy says that by 1918 New York's subways were already using "dead man's controls," which stop the train if the driver is incapacitated. And some had controls that automatically slowed a train that was going too fast, especially downhill. But unfortunately, "the line over which the fatal train was operating did not have such hardware," Cudahy says.
3. Chicago, 1977
The Crash: The Windy City's most catastrophic rail accident came in 1977, when three cars fell off the elevated tracks after two trains collided at the Ravenswood stop downtown.
Chicago had just installed a system that made a train brake automatically if it sensed another ahead, much like what was supposed to happen but didn't in the D.C. accident Monday.
However, Chicago operators back then could override the stop signal if the train were traveling at less than 15 miles per hour. And because "ghost signals" happened occasionally, many drivers did roll past red lights.
"The system interpreted the station stop as the required stop, and so the motorman should have been operating under 'sight rules,'" Cudahy says. "But he didn't. And he didn't even keep his eyes on the track ahead."
The Lesson: In the aftermath of this wreck, the Chicago Transit Authority changed the rules and forbade operators from proceeding on their own. From then on, they would have to call Central Control before proceeding through a stop sign.
4. England, 1988
The Crash: Great Britain has seen plenty of rail accidents over the years. The deadliest in recent times happened near Clapham Junction in southern London. Thirty-five people died in a rush-hour collision of two trains carrying an estimated 1,300 people between them.
The Lesson: An inquiry into the accident recommended that the entire British rail system install an automatic train protection system. But the government balked at enormous bill — nearly $1.5 billion — and instead privatized the rail system.
5. Australia, 1999
The Crash: Another disaster on a curve occurred in 1999, this time near Glenbrook, New South Wales, Australia. After stopping at a signal, an intercity passenger train came around the bend and ran into the back of an Indian Pacific long-distance passenger train, killing seven and injuring 51.
The special commission of inquiry report cited several problems that led to the crash. First, it noted, "there has been a general failure in New South Wales organizations to embrace advances that have been made in the management of rail safety internationally and in other industries."
However, in this case the more important problem was the failure of communication. Before the accident, while sitting at the stop signal, the driver of the intercity train reportedly asked the signaler, "I'm going past it am I, mate?" The signaler replied, "You certainly are," and the driver took off, only to hit the Indian Pacific train parked at another red light further up the road.
While the two trains shared the same track, they used totally different communications systems and couldn't talk to each other. So the intercity train driver had no idea the other train was up ahead until he pulled around the corner and saw it, but by then it was too late. And when the Indian Pacific driver tried to call the signaler before the accident, he didn't get through.
The Lesson: In 2004, the Australasian Railway Association put together a plan to unify communications for all its rail lines.
6. Baltimore, 2001
The Crash: People aren't the only cargo endangered by rail accidents. In 2001 a cargo train carrying hazardous materials caught fire in the Howard Street tunnel in Baltimore, burning for three days with temperatures as high as 1,800 degrees Fahrenheit.
The Lesson: The Baltimore train wasn't carrying spent nuclear waste, but other trains that pass through that tunnel do carry such cargo.
The state of Nevada and the National Science Foundation both issued reports in 2003 stating that a nuclear fuel disaster in the area could contaminate 32 square miles, and that the Baltimore fire in 2001 appeared to exceed the temperatures that casks carrying spent nuclear fuel could withstand.
However, a report by the Nuclear Regulatory Commission disagreed, finding that no nuclear fuel would have been released in such a fire.
7. South Carolina, 2005
The Crash: America's next toxic train disaster spilled liquefied chlorine in Graniteville, S.C. A cargo train collided with a parked locomotive because a switch was in the wrong position.
The Lesson: As a result of that wreck and others like it, the Next Generation Rail Tank Car Project is rolling out new designs for cargo cars that could minimize the damage from these disasters through use of double walls, crumple zones and stronger steel.
8. Japan, 2005
The Crash: More than 100 people died in 2005 when a train jumped a curve in Amagasaki, Japan. The rail company, JR West, admitted the accident could have been avoided if the train had been equipped with an automatic stopping system to prevent the operator from taking the curve too fast.
The Lesson: The accident also provided a cultural lesson. While the driver took the blame for taking a corner 46 kilometers per hour faster than he should have, the rail company took flack for putting too much pressure on its drivers.
Before the accident, conductors who made mistakes were forced to go through "re-education programs," so they were under intense pressure to keep on schedule.
9. Los Angeles, 2008
The Crash: It's calamitous enough when one train rear-ends another, as happened Monday in Washington. But it's often deadlier when two trains meet head-on.
That happened last year in Chatsworth, Calif., when a Metrolink commuter train met a Union Pacific freight train and 25 people died. The investigation concluded that the Metrolink operator missed a signal that he wasn't clear to enter a single track area because the freight train had right-of-way.
The Lesson: Kathryn O'Leary Higgins, chairwoman of the National Transportation Safety Board panel that probed the crash, said she found four major safety violations leading to the crash (for one, a conductor was texting just before the crash). Metrolink will soon install cameras on its trains to monitor operators and engineers.
10. Staten Island, 2008
The Crash: And then, there's always simple operator error. Last December, an MTA train derailed on New York City's Staten Island after the operator, who had just had more than eight hours off to celebrate Christmas between shifts, missed a safety stop and then crashed into a steel bumper.
In the final seconds, she reached for the emergency brake but pulled the air horn instead. The train was out of service, so no passengers were on board. But the train operator lost her job.
The Lesson: Make sure that train operators are getting enough sleep.