Authorities have confirmed that the lady, aged in her 60s, who was killed by a train on the Ballina to Dublin line yesterday died after she ran onto the tracks to rescue her dog who got off its lead.
The tragedy happened at a level crossing at Knockshambally, near Straide, at 11:30am.
The woman was pronounced dead at the scene by emergency workers.
Gardai have opened an investigation into the incident.