A mother-of-five has been killed in a fireball at a petrol station as her helpless kids looked on after an elderly woman reversed into the pump she was using.

The incident took place at a Shell petrol station in Palm Harbor in Pinellas County in the US state of Florida at around 2pm on Wednesday.

The Florida Highway Patrol said the victim, Shoi Delfin-Caballes, was filling up her car when a 66-year-old woman reversed into the pump she was using, knocking it over.

The mother-of-five was pinned between the collapsed pump and her car while still holding the nozzle when a huge fireball was sparked.

Police spokesperson Steve Haskins said the victim’s 15-year-old daughter and 11-year-old son were in the car at the time, adding that they jumped out and tried to rescue their mum.

An onlooker pulled them away when the fire grew too strong.

Eyewitness Jared Pierson said he rushed across the street when he saw the kids trying to put out the flames with an extinguisher and pulled them away in fear that the petrol station could explode.

He said: “By the time I was crossing the street, it was all a giant fireball. All I could do was pull the kids away.”

The children then told Pierson that their mother was still trapped in the fire and he and a friend managed to get close to the burning vehicle, but could not find the woman in the flames.

The woman who reversed into the pump was not found to be over the alcohol limit and as such no charges have been filed against her.

Following the victim’s death, her son Seth said: “For everyone reaching out, my family and I thank you for your kind words and loving messages.”

The investigation into the incident is ongoing.