"I think my heart came up, and I swallowed it. I was petrified," said Wanda Stead, who unexpectedly caught the collapse on video on Tuesday while she was enjoying a day on the Bay of Exploits with her husband. The couple, who live in Gander, have a cabin in Cottlesville.
Stead's video shows how the arch in the iceberg suddenly began to crack, and within seconds, tonnes of ice had fallen to the bay below.
Stead's voice is audible in the video, with a blood-curdling instruction to her husband: "Run, Rick, go — go!"
With her husband hitting their boat's engine, the couple were able to move to a safer position, although Stead told CBC News on Thursday that her impression at the time was that their lives were in immediate peril.
"All I could see was this tidal wave coming toward us," she said.
Wanted to warn others
It may not have turned out to be a tidal wave, but the bay's waters changed immediately, with a powerful wave discharged in moments.
Stead said she shared the video to warn others of the dangers of approaching icebergs.
"We were too close," she said, estimating that they had parked their boat between 100 and 150 feet — or 30 to 45 metres — away from the iceberg.
"Accidents are unplanned events," she said. "You never know with something that big … and people need to know."
Stead said that she felt rattled and drained by the end of the ordeal, but that, to her surprise, her video did not show much shaking.