A teenage boy died saving his girlfriend from an oncoming train as the pair walked on the train tracks near their California school Friday.

The teen, whose name has not been released, was headed to a Sadie Hawkins Day dance with his 16-year-old girlfriend, Mickayla Friend. It's not clear why they were walking along the train tracks, but according to reports, neither teen noticed the train until it was too late.

"The engineer was on the horn," said Sean Stark, who saw the incident happen. "Then finally, they both looked back at the same time."

Stark said the teenage boy made a split second decision.

"They would have both been underneath that train if he didn't push her out of the way at the last second," said Stark.

Police say keeping people off the tracks, which run close behind a little league field, has been a challenge.

"Sometimes these trains, when you're directly in front of them, can sneak up on you," Marysville Police Chief David Baker told ABC.

Friend is currently in critical condition.

[image via KCRA]