From the beginning, Tin Nguyen's family had hoped she wasn't at work.
They knew her boyfriend, Hansin Trinh, was celebrating his birthday Wednesday and wanted desperately to believe Nguyen was with him and not at the holiday party at the Inland Regional Center.
"That day she never called me," Vanessa Nguyen, Tin's mother, said. "I called her a lot but she never answered."
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Vanessa said her daughter's phone just kept ringing after Vanessa heard that there was a shooting at the San Bernardino center for developmental disabilities.
After the shooting, busloads of survivors arrived at the Hernandez Center. But 31-year old Tin wasn't there.
"We called to every hospital hoping that maybe she might be there or maybe not be there, but we didn't know," Trung Do, Tin's brother, said.
Tin's family said she had her life planned out.
She was to be engaged to Hansin Trinh by the end of the year. They talked about having children, and inviting her mother to live with them just as she had been raised.
Tin was later identified by her fingerprints.
The mass shooting that the FBI was investigating as an act of terror left 14 dead and 21 injured.
It was one of the deadliest shootings since 27 children and adults were killed in Newtown.