BART tweeted out that a person on the tracks was killed.
Trains were briefly being turned around before arriving at Bay Fair, but as of 3:09 p.m. they're single-tracking through the station, according to a BART spokesperson.
The Bay Fair station is now back open, but residual delays continue systemwide.
Stay with ABC7 News for the latest details on this developing story.
Bay City News contributed to this report.