VANCOUVER -- Hours after a tragic accident in B.C.'s Fraser Valley that left two children dead, a Good Samaritan stayed at the scene to honour a heartbreaking request from their grieving mother.

Squamish resident Joy Pringle stood in the rain at Foley Lake Sunday as crews worked to recover the young victims' bodies from the water.

"I promised the mom that I would stay and be there when the kids were extricated," Pringle said in an emotional video she posted online. "Police are here right now with search and rescue and the dive team, and I'm waiting to honour what I told the parents I would do."

Officials said the victims are a nine-year-old girl and 10-year-old boy from Abbotsford. The family was off-roading on an ATV when the vehicle overturned and crashed down an embankment into the lake on Sunday.

The parents and a 13-year-old managed to make it out alive, but the younger children were not so lucky.

Pringle was just one of several people who rushed to help in the aftermath of the accident. She had been camping nearby with a friend, and was starting to pack up when the teenager rode up on a dirt bike and told them what happened.

Pringle told CTV News they ran to the top of the embankment, then she scrambled down to the lakeshore and headed onto the water to try and rescue the missing children.

"I swam over to where I could see bubbles coming from the water," she said, adding that it was too dark to see below the surface.

The Good Samaritan then dove in and felt around, but could only reach what she believed to be the tires on the upside-down ATV before she ran out of air and had to rush back to the surface.

"I realized at that point I wouldn’t be able to rescue them," she said, her voice breaking.

By that point, it would have already been at least 10 minutes since the crash, based on how long it took the friends to reach the embankment.

Pringle, her friend and some fishermen then banded together, offering clothes, blankets and other emergency supplies to the survivors. She said the family was "pale, blue and hypothermic" after being in the chilly water.

"We all took care of each other," Pringle said. "I'm glad that I was there and I'm glad that I could help, and I wish I could have done more."

When it was finally time for the family to leave, the devastated mother asked Pringle to stay, and she agreed. She said the experience left her feeling a strange closeness to the family, even though they just met.

"They will always have a friend in me, and if they need or want anything I will be there, 100 per cent, and they know that," said Pringle.

The tragedy came at an emotional time for Pringle as well. She told CTV News her deceased sister would have turned 25 on Tuesday.

"Life is so short," she said in her Facebook video. "Say you love your loved ones, hug your loved ones. It can all change in a minute."

Police said all of the survivors were taken to hospital and are in stable condition. The have confirmed everyone on the ATV was wearing helmets and seatbelts at the time of the accident.

"A day of recreation turned in to every parent’s worst nightmare," Sgt. Krista Vrolyk said Monday. "There is no indication of any criminality. This is honestly a very horrific tragedy."