Police siren
A city fire department spokeswoman said the five victims were ages 2, 4, 5, 11 and 13. Their names weren't immediately released Sunday. Image Credit: Pexels

Then, any parent's worst nightmare happened.

Arizona: Like many families, they were preparing for the holiday season, with dad shopping for gifts and the kids spending time together at home.

Over the weekend, a blaze engulfed a family home in Bullhead City, Arizona, killing all five children inside while their father was out shopping for groceries and Christmas gifts, officials said.

The victims - four young siblings aged 13, 5, 4 and 2 and an 11-year-old visiting relative - had all been in the upstairs bedroom of their two-story duplex when the fire started shortly before 5 pm on Saturday, the Bullhead City Police Department said in a Monday statement.

Initial investigations found that the fire originated in the downstairs foyer and traveled up the only staircase inside the house, "preventing the victims from exiting," the police statement said, adding that the cause of the fire remained unknown.

Several neighbours reportedly tried to rescue the children, including by placing a ladder toward the upstairs bedroom where the children were gathered, but to no avail, police said.

The fatal fire has plunged the small city of 42,000 near the Arizona-Nevada border into shock and grief.

The father told investigators he had gone out for around 21/2 hours to shop, police said. Authorities have neither named the father nor the children, who are pending identification by the Mohave County Medical Examiner's Office, but said the victims' grandfather was an employee of the city's fire department.

"That's five, innocent children that had nothing but the lives ahead of them. You don't process that, it doesn't make sense," local resident Shawn Jacobson told Fox 10 Phoenix.

Another resident, Brittney Froud, said she lived across the street and was struggling to process the loss. "I could just hear the dad sobbing on the street," she said. "That was just heart-wrenching to hear."

"This tragedy has shaken the community," Mayor Steve D'Amico said in a video message.

"I want to express my deepest condolences on behalf of myself and the Bullhead City community to the grieving families of the five children who lost their lives," he added. "Your loss is the community's loss and we're grieving with you."

A candlelit vigil is scheduled to take place Wednesday, and photos showed an area outside the house inundated with flowers, soft animals and candles.

Locals set up a campaign fund for the bereaved families, while one funeral home volunteered to cover all the funeral expenses, D'Amico said.

A local school identified one child as Henry Lewis, one of their fifth-graders. Jamaica Elementary PTSO said it was "heartbreaking" news and added that counselors would be present at the school to support staff and students.

"Out city is dealing with a horrific tragedy," Bullhead City Chief of Police Robert Trebes told reporters Monday, adding that investigations into the cause of the fire were ongoing.

"Now is the season where we should be spending time with our loved ones and embracing the joys of the holidays," he said. "However, our community is suffering."