Experts suspect yesterday’s deadly subway collision in Washington was the result of both a system failure and human error, the Washington Post reports. The city’s trains are run by onboard computers, which should, theoretically, prevent trains from colliding. The system has failed once before, in 2005, but the operators hit the emergency brakes in time. It appears yesterday’s operator did not.
With the trains above ground and the weather clear, the operator should have seen the other train. “That’s why you have an operator in the cab,” said one train safety expert. “She should have been able to take action. That’s what they’re there for.” The incident hasn’t been fully investigated however; it’s also possible the driver was somehow incapacitated, or that the braking system failed. (Read more subway accident stories.)