A 15-year-old girl fatally struck by a train in Texas had posted a final farewell on her Instagram account only hours before.

"I love all of y'all. Never forget it!" Fort Worth teen Megan Whisenhunt wrote with an attached black-and-white photo of herself smiling on Thursday.

Police confirmed Friday that they are investigating her abrupt death as a suicide.
"There is evidence to indicate that she was attempting to commit suicide when hit by the train," police said in a release.

Authorities said that around 8:30 p.m. they were dispatched to where a pedestrian was reported as hit by a northbound Fort Worth & Western train.
The teen had been sitting on the railroad tracks when the train sped through, said police.

She was recovered in critical condition and transported by CareFlight air ambulance to a local hospital where she was pronounced dead.
The teen's dually shocking and heart-wrenching death was expressed by commenters on her Instagram photos. The majority of the photos — the most recent posted hours before her death — appear to show her happy and surrounded by friends.

Authorities have not released any known motive behind her death.