Los Angeles: Perhaps the most remarkable thing about the collision between a Southern California commuter train and a truck abandoned on the tracks was this: No one died and only eight people on board were admitted to hospitals.
Officials with the Metrolink train system credit cars designed to blunt the tremendous force of a head-on collision.
Accident investigators have not yet said what role "crash energy management" technology played in Tuesday's wreck. But the fact that so few among the 50 people on board were seriously injured is prompting other commuter train systems to take a renewed look at safety technology that has been around for at least a decade but still is not widely used in the United States.
A spokesman for Metro-North, the New York City commuter railroad where a fiery collision between an SUV and a train February 3 killed six people, said the California crash will prompt Metro-North "to assess whether the system could be beneficial in enhancing safety."
It is not clear whether the technology would have made a difference in the most recent Metro-North crash, in which more than 400 feet of electrified third rail snapped into a dozen sections and speared the train. The Metro-North passenger cars meet federal design standards but do not include crash energy management systems, spokesman Aaron Donovan said in a statement.
Back in California, Metrolink officials are crediting crash energy management, which was designed and built into three of the four double-decker passenger cars involved in the accident, with the remarkably low number of serious injuries even though the impact at an estimated 55 mph was violent enough to fling several cars onto their sides.
"Safe to say it would have been much worse without it," Metrolink spokesman Jeff Lustgarten said of how the technology performed during the crash in Oxnard, about 65 miles northwest of Los Angeles.
The safety systems can vary in design, but the general idea is to disperse the energy of a crash away from where the passengers sit. Metrolink's cars have collapsible "crush zones" at the ends of its cars that help absorb the impact, along with shock absorbers, bumpers and couplers.
It is the same principle at work in the "crumple zones" in newer cars. They are designed to absorb the force of a crash while keeping people inside safe.
Nearly a decade ago, the US secretary of transportation stood at the site of a horrendous Metrolink crash near downtown Los Angeles and called for the widespread adoption of this kind of train car.
In response to that 2005 accident in which a train smashed into an SUV in Glendale, killing 11 people, Metrolink bought dozens of new passenger cars equipped with these systems.
In 2010, the first of those cars rolled into use. By June 2013, the system had 137 of the cars - about two-thirds of its fleet - bought for $263 million from South Korea's Hyundai Rotem Inc., Metrolink spokesman Scott Johnson said.
While federal regulators for years have weighed rules that might require the technology, they have not formally proposed such measures for trains with a top speed of less than 125 mph. Rules are in place for a small subset of trains that can go faster.
Aside from Metrolink, crash energy management equipment is used by Amtrak, including on its Acela line in the Northeast, and two systems in Texas, according to the Federal Railroad Administration.
One obstacle to more widespread use of the train technology is that it has to be designed into new passenger cars, and railroads that bought cars without it in recent years may not want to invest in new ones so soon. Railroads can't simply retrofit existing cars.
"It is not a bolt-on device," said Martin Schroeder, chief technology officer for the American Public Transportation Association. He has been working with the Federal Railroad Administration as it considers whether to propose rules for the systems.
The advisory committee on which he sat finished its work in 2010. The Federal Railroad Administration would not comment Wednesday on the status of possible regulations.
Meanwhile, federal investigators looking into the Southern California wreck focused on the man who drove his pickup truck onto the tracks, then abandoned it as the train approached before dawn. Jose Alejandro Sanchez-Ramirez, 54, was arrested on suspicion of leaving the scene of an accident.
Ron Bamieh, an attorney for Ramirez, said his client did all he could to try to free the truck, then ran for help. But National Transportation Safety Board member Robert Sumwalt said late Tuesday that the truck was not stuck in the sense that it bottomed out on the tracks. He also noted that its emergency brake was on.