It happened just before 2 p.m. near Long Beach and Vernon avenues.
According to the Los Angeles Fire Department, the pedestrian was found dead at the scene and was removed from under the Metro A (Blue) Line light rail train. Metro officials told ABC7 the train was heading southbound at the time of the crash.
There were 42 passengers on the train but no one was injured.
A Line trains are still running, but they're sharing a single track between the Washington and Slauson stations.
This is a developing story. This article will continue to be updated as more information becomes available.