SAN ANTONIO — A San Antonio mother’s death is under investigation after she passed out on a railroad track and was then struck by a train.

Police say the incident happened around 5:30 a.m. Sunday at the train tracks near Walzem Road and Interstate 35.

First responders were able to take Sierra Barber to a nearby hospital in critical condition, but she later died. Pacific Union was also called out to the scene to determine what happened.

Authorities still don't know why the woman passed out on the tracks.

According to a GoFundMe* page set up by Barber’s sister, circumstances of how she ended up on the train tracks are still unknown.  

“We would like to be able to give her a proper service and burial, but we do not have the funds to do so.  I ask for your help and prayers during this traumatic time in our life,” the page says.

Sierra is survived by her children; Nevaeh Lopez, Jenevie Lopez, mother; Jennifer Dulaney, siblings; Alexis Talley, her husband Houston Talley, and their son Talon Talley, Hope Sanchez, Salvie Sanchez, Faith Sanchez and Kloe Sanchez.

The family has set up a GoFundMe account to help with funeral expenses. If you'd like to donate, visit here.

*This Gofundme.com site is not managed by Spectrum News. For more information on how the site works and the rules visit gofundme.com/safety.