PORTLAND, Ore. - A portion of TriMet's eastbound MAX line was shut down Monday evening after a woman was struck and killed by one of the trains.

The incident happened around 6:15 p.m. near the 82nd Avenue Transit Station along the Blue Line.

Police and fire were on the scene and TriMet shut down the eastbound line while investigators tried to figure out how the woman, whose identity is unknown at this point, ended up on the tracks. 

The area is fenced on one side, but someone could easily jump over the Jersey barrier on the Interstate 84 side. 

"It's too early to tell right now what exactly what was going on with the person who was in the (train's) right-of-way," said Josh Collins with TriMet.  "We'll have to work with local law enforcement to assist in any way we can."

Witnesses reported seeing the woman walking along the tracks with her back to the train.  There were some reports that she was on a cell phone when she was struck.  Here are some of the reports from passengers on the MAX train:

• "She was walking, obviously, right next to the tracks.  Maybe confused, lost." - Jennifer Gilmartin
• "You could hear the driver honk his horn and it sounded like he yelled "no!" and then you just heard a thud, like he hit somebody." - John Drag
• "She was crossing from the highway, across the tracks, and she got hit.  We heard the hit and then we felt the bump." - unidentified MAX passenger
• "All of a sudden we felt this big bump and knew we'd hit something.  And we overheard him say something that she was on her cell phone crossing from the freeway going over the landing." - Jeannie Millington

Service was disrupted between the Northeast 7th Avenue Station and the Gateway Transit Center for several hours Monday night and buses shuttled riders between stations.  The eastbound line reopened late in the evening.

The investigation continued on Tuesday.