An ice-cold wall of water rose so quickly that expat Suzanne Morris had seconds to escape her Colorado apartment in the middle of the night last Wednesday.
Ms Morris, formerly of Auckland, and her American husband Jeff Voreis are among tens of thousands of people left homeless in the city of Boulder, at the base of the Rocky Mountains, by flash floods which have hit the region since last week.
The couple had been monitoring a small stream near their ground floor apartment and the water had been rising through the night, but they were completely unprepared for the surge that arrived.
"It was like a tsunami, it just kept coming and coming. It begins to flood and you think it will stop at 2 feet or 3 feet but it doesn't. It was a torrent," Ms Morris told the Herald.
"It was cold and dirty and just full of debris ... our ranch slider shattered as it came rushing through and ... the velocity of it was really unbelievable, the water itself punctured holes in the dry wall and it was like a fire hydrant into our neighbour's apartment.
"We had a couple of seconds to figure out that we had to run."
It was about 1am when the couple fled their apartment and heard their neighbour screaming for help. They waded through waist-deep water to her bedroom, where she was trapped.
"We had to bust her door open a little bit to let her out. After we got her out, the door slammed shut on my hand and I was stuck in the door for a little bit, I thought I was going to die down there, it was terrifying."
Ms Morris, a speech therapist who has lived in the US since 2005, was lucky not to break any bones. Mr Voreis needed stitches for cuts to his legs and arms. The couple's apartment will take up to six months to put right.
Ms Morris and her husband have been staying with friends and are unable to work as most of the city remains underwater.
At least four people have been killed since the floods began last week. There are reports of more than 1000 people still awaiting rescue in some areas and more than 19,000 homes have been destroyed.