A Toronto family is "very lucky" to have escaped unharmed after a broken water main quickly flooded their home overnight Thursday.

Around 2 a.m., Tina Gilbert got up from bed to use the washroom in her family's apartment on Dixon Road in Kingsview Village, and knew immediately that something was wrong. She was submerged up to her shins in cold water.

She panicked, knowing that small children were sleeping in another room. Before she had time to gather herself, the water had reached her knees. Eventually, the door to her bedroom burst open.

"It was crazy. It was a lot of water," Gilbert said.

The four adults in the home gathered and went to where the children were sleeping. By that point, the water had gotten so high that they couldn't open either exterior door into their basement unit.

"The only thing I was worried about was getting my kids out safe," said Monique Gilbert, Tina's sister.

The children were lifted out of the apartment to safety, on street level, through a window that the whole family eventually used to escape the home.

The experience was terrifying for everyone, said Tina's mother Opal Gilbert.

The water level rose so high that firefighters were unable to open the door to get into the apartment. (James Morrison-Collalto/CBC)

"They are so traumatized right now. My grand kids are just crying, crying, crying," said Opal. "Everything is gone. We don't even have clothes. We are cold. We need help," she continued through tears.

According to Toronto fire District Chief Vernon Hiller, the sudden flood was caused by a burst water main. Water flowed into the apartment through a different window. Crews got to the home around 2:25 a.m., he said.

"When we arrived, we couldn't even open the door because the water level was so high in the apartment that the pressure was keeping the door closed," Hiller said, adding that the family was "very lucky" that no one was electrocuted during their escape.

Crews managed to turn off the water and electrical supplies to the property fairly quickly, but not before more than three feet of water pooled in the home.

The Gilbert family says they've lost most of their material possessions and important documents to the flood. (James Morrison-Collalto/CBC)

Hiller said that the city will need to repair the water main before the building's supply can be turned back on.

Broken mains are a frequent issue in Toronto during the winter months, as the city increasingly relies on aging and outdated water infrastructure.

"It's weather related. We've had numerous calls like this across the city with rising and lowering temperatures. It's just thawing ice and pipes — so it's not uncommon to have this happen," Hiller said.

The Gilberts say they will now need to figure out where they are going to stay as insurers assess the flood damage. The family says they've lost nearly all of their belongings and important documents.

"We tried to get things out, like papers and things like that. But the water came in in a split of a second and we couldn't save nothing," said Monique.

The family's superintendent told CBC Toronto there is an apartment they can use in the coming days.