Wednesday marked one year since the "Tragedy on the Tracks," the deadliest crash in Metro-North history that left six people dead in Valhalla.

On Feb. 3, 2015, a Metro-North Harlem line train packed with hundreds of evening commuters slammed into a Mercedes SUV at the Commerce Street grade crossing.

Officials say the SUV driver, Ellen Brody, of Edgemont, drove onto the tracks as the train crossing gate came down on her vehicle.

The fiery collision sent the electrified third rail into the first car of the train. Five passengers, all in the first car, were killed along with Brody. Fifteen more people were seriously injured.

One year later, it is still not known what caused the deadly crash. The National Transportation Safety Board released some of its findings in December 2015, and it expects to release its final report soon. It doesn't necessarily assign blame, but it will make safety suggestions to try and prevent another accident from happening again.

A few things have changed since the crash. Metro-North has launched a railroad crossing safety program that deals with education, enforcement and engineering. It has handed out more than 4,900 rail crossing safety pamphlets and issued more than 1,800 summonses.

It is also taking a closer look at rail crossings across the state. The town of Mount Pleasant is also looking into its three rail-grade crossings and trying to determine if they are safe enough to leave open or not.