NEW YORK (CBSNewYork/AP) — Grief counselors were on hand Monday at a Bronx elementary school as investigators try to determine what caused a driver to plow into a group of trick-or-treaters, killing three people, including a young girl and her grandfather.

“I had a lot of dreams for Nyanna. I had so many plans for her,” Natalia Perez said the day after her daughter, 10-year-old Nyanna Aquil, was pronounced dead at a hospital. The victim’s 3-year-old sister also was hospitalized.

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Perez’s 65-year-old father, Louis Perez, suffered severe head trauma and died at the scene Saturday night when the car jumped a curb in the Morris Park section of the Bronx, leaving behind mangled bodies and bloodied costumes as neighbors ran to help.

Another man, 24-year-old Kristian Leka, also was killed. His 9-year-old sister and a 21-year-old female friend were injured, but not critically. Leka reportedly pushed his sister out of danger.

As a crowd gathered for a candlelight vigil at a street corner in the Bronx on Sunday night, police were examining whether the driver, Howard Unger, 52, driver may have suffered a medical emergency, such as a seizure.

According to police, Unger takes two medications for seizures, but he said he hasn’t had a seizure in 12 years, CBS2’s Matt Kozar reported.

Police confirm the driver was on seizure medication, CBS2’s Janelle Burrell reported.

The black Dodge Charger plowed into the pedestrians on a sidewalk and then smashed through a fence in front of a home, police said. The driver was taken to the hospital in stable condition. No charges had been announced as of Sunday night, police said.

Witnesses described hearing a loud boom, followed by screaming and crying.

Just hours before the collision, Perez snapped a selfie with her daughter.

“Nyanna was the best daughter in the world,” the mother said. “She was gorgeous, she was sweet, a little bit shy, but she was going to be a star.”

Candles, flowers and teddy bears were left at the scene of the crash, where the makeshift memorial continues to grow as people from the community come to pay tribute to the victims.

“It just makes me so sad,” Morris Park parent Tawana Taylor said. “I can’t imagine what the mother is going through to lose her father and her daughter, I can’t imagine.”

“I cried, it could have been one of my own,” said parent Janine Dodson.

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A local priest prayed for the victims and blessed the crash site Monday.

“This is a place where such a terrible event happened, but now it has become a place of prayer and peace and that’s because of the faith of the people,” Father Matthew Reiman said.

On Monday, her classmates at P.S. 83 returned to school for the first time without her.

“Everyone in her school loved her, her spirit, her smile, her presence were amazing,” Perez said.

Perez said her father had taken her daughters out for a second round of trick-or-treating while she was at work.

“Life is short. Life is very precious, and you have to always, always remember to love people, hug your loved ones,” she said. “Don’t argue don’t fight, don’t waste any moments with them.”

Perez said she doesn’t want her daughter’s wake to be a sad occasion.

“My daughter, she was going to be 11 in January. She loved the color blue,” she said. “I definitely want everyone to wear blue at her wake, and I want to have a really great, rejoicing celebration of her life.”

A funeral will be held for victim Kristian Leka on Tuesday.

“He always put other people over himself, and he helped people at any chance he got,” Greta Luka, Leka’s girlfriend told CBS2’s Valerie Castro.

“I just remember the big black car coming towards us, and then a big shove from him to push us over,” Luka said. “He definitely, definitely saved our lives.”

Arrangements for the Perez family have not been finalized.

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