Man struck, killed by train in La Puente

 An unidentified man sitting on the railroad tracks was struck and killed by an Amtrak train Sunday afternoon in La Puente, authorities said.
   The train’s crew spotted the man on the tracks near Old Valley Boulevard and Albert Street and tried to warn him by sounding the horn, but the train could not stop quickly enough to avoid hitting him,  the Los Angeles County Sheriff’s Department said.
   Investigators are looking into whether the man intended to commit suicide or was intoxicated, among other possibilities, said Sgt. Tom Wilson of the sheriff’s Industry Station.  
   The 3:30 p.m. incident occurred a short while after the Sunset Limited train, with 184 passengers,  left Union Station in downtown Los Angeles headed for New Orleans. No passengers or crew members were hurt, and the train resumed its journey about 8 p.m., according to  Danelle Hunter an Amtrak spokeswoman.