LOS ANGELES (CBS/AP) — A Los Angeles man and the woman he had proposed to in Paris at Christmas were among the 10 dead in the crash of a bus that was taking high school students to his Humboldt State University alma mater, his grandmother said Friday.

Michael Myvett, 29, and fiancee Mattison Haywood were serving as chaperones on the bus that was traveling from Southern California to Humboldt State when it was hit by a FedEx tractor-trailer and exploded into flames.

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“He just died,” grandmother Debra Loyd told The Associated Press, her voice cracking. “He was my grandson, the greatest grandson any grandparent could ever have.”

She said she got the call from authorities in the late morning Friday, and they asked for dental records to confirm his death.

Myvett had given Haywood her engagement ring outside the Louvre on Christmas Day, said his employers at the Center for Autism and Other Disorders in Torrance.

Myvett had provided therapy for autistic children for the last two years, center spokeswoman Stacey Price told AP.

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He was “able to connect with our kids on a level few others could, and he contributed to their wellbeing in such a positive and profound way,” the center’s operations manager Kyle Farris said in a statement.

A third chaperone killed in the crash, Humboldt State recruiter Arthur Arzola, was identified earlier Friday. The drivers of the bus and tractor-trailer and 10 students also died, but their names have not been released.

Arzola, 26, of Rancho Cucamonga was pronounced dead at a Sacramento hospital, coroner’s officials said.

Arzola was an admissions counselor for the Northern California university who lived and recruited students in the Los Angeles area.

In his online bio for the job, he called himself thoughtful, compassionate and friendly, and said he liked to walk on the beach when he visited Humboldt.

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A university statement praised him for his passionate commitment to helping low-income and first-generation students get into college.