Metropolitan Transportation Authority spokesman Sam Zambuto says the two female victims were struck on the tracks just west of the Copiague Station on the Long Island Rail Road's Babylon Branch at about 6:30 p.m. Tuesday.
The victims were identified as Ariana C. Napolitano and Katherine Sanchez, both of Copiague.
Officials are not sure why the teens were on tracks, which are located atop an elevated embankment.
"She never go over there. I don't know why," Carlos Sanchez, her father, said.
Sanchez can barely put together words. His 18-year-old daughter had her whole life ahead of her.
Sanchez and her friend, 18-year-old Ariana Napolitano, were up on the LIRR tracks in Copiague on Tuesday evening when they were hit by a passing train.
Local teens say it's not uncommon for young people to hang out on the tracks.
"She actually she had plans with me last night to go to the movies with her older sister. We just don't know," Shari Candelario said.
Sanchez and Napolitano both graduated from Copiague High School last year.
Napolitano's family members tell Channel 7 that she had just gotten a job at Staples and was on her way to buy her first car.
Sanchez had lupus, but her uncle says she never let the disease stop her from enjoying life.
"Kathy was just lovable, outgoing. Just trying to be with everyone at once," Rafael Sanchez said.
"She just wanted to live everyday like it was her last because she never knew when it was coming," Candelario added.
There were no passengers on the 12-car train, which was headed to a railroad yard in nearby Babylon.
The Metropolitan Transportation Authority police are investigating.
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