Train conductor desperately tried to warn three friends he saw taking selfie before they tragically died

A train conductor desperately tried to warn three friends who were taking a selfie on the tracks before they died.

Back in 2011, Essa Ricker, 15, Kelsea Webster, 15, and Savannah Webster, 13, were killed in a tragic accident.

Essa Ricker, Kelsea Webster and Savannah Webster were killed in a tragic accident (Getty Stock Image)

The friends had been waving to engineers of the Utah Railway train as they ventured past the Covered Bridge Canyon crossing in the state.

But they had no idea that a different train - a Union Pacific carrier - was traveling in the opposite direction behind them.

Shortly before the accident, Savannah wrote on Facebook: "Standing right by a train ahaha this is awesome!!!!"

The three teenagers posed for a selfie, unaware that behind them a train was quickly approaching.

The selfie taken just seconds before the tragic incident sees headlights from the fast approaching train creating a halo.

The teens tragically lost their lives (Union Pacific/Essa Ricker/Kelsea Webster/Savannah Webster)

At the time, John Anderson was working as a train conductor, meanwhile engineer Michael Anderson was also on board.

Michael tried to blast the horn but the girls didn't hear.

"They were in their own little world," said John, who explained both he and Michael were yelling as the train neared closer.

"We watched in horror as we got closer," he told Union Pacific.

"We saw them for about 12 seconds until they disappeared from our sight and the train continued moving forward."

Trains traveling at 55mph can take over a mile to fully stop, even after the emergency brakes are activated.

A train conductor desperately tried to warn the girls (Getty Stock Image)

John sprinted to the track after the train came to a stop and found the first girl had no pulse.

He also came to the realization the second teen was no longer alive, so headed over to Savannah.

She was badly hurt, but alive.

"I told her everything would be OK and she relaxed a little," the conductor reassured the teen.

"I hoped she would make it and for some reason I really thought she would."

Savannah underwent surgery at a local hospital, but after doctors told her parents she would not recover from severe brain injuries, life support was withdrawn.

Jayna Webster, Savanah and Kelsea's mom, wrote on her blog at the time: "We spoke to the doctors today and they informed us that Savvy's brain injuries were too great.

"Even though they've had done everything possible, Savannah will not be able to recover any further. We will keep her on life support till the end of the day, but it's time to say goodbye, for now, to an angel that walked among us."