The Altamont Corridor Express told riders via the comments section on their Facebook page that the collision was a fatality.
ACE Train spokesperson Thomas Reeves told Patch, via email, that the person on the tracks was a "trespasser."
"Trespasser in Livermore struck by ACE 06 around 5:40. Livermore PD investigating."
Livermore Pleasanton Fire Battalion Chief Paul Legasa says fire crews responded to the call of a pedestrian versus a train with two engines, one truck, and a Battalion Chief.
The Union Pacific Railroad Police Department is investigating the incident and has not yet been reached for comment.
The identity of the victim has not yet been released.
According to the ACE Train Facebook page, the trains were running again by about 8:30 p.m. last night. As of this morning, the ACE Train website shows all trains running on time.
In January, 65-year-old Benjamin Cordova of Livermore was killed when he was hit by the train about two blocks away from Tuesday's fatality. On Jan. 20, a Pleasanton man died after being hit by the Caltrain in Santa Clara during his heroic efforts to save another man who was suicidal. On the peninsula, a woman was killed after being struck by the Caltrain on Jan. 31
- Man Killed After Being Struck by ACE Train
- Officials Identify Man Struck by ACE Train
- Pleasanton Man Died a Hero Trying to Save Suicidal Man
- Caltrain Service Resumes After Fatally Striking a Woman
Patch will update this story once more information becomes available.