Houseboat with 25 family members aboard bursts into flames and sinks

A family of 25 enjoying a day out on the lake were interrupted by a loud boom that changed the trajectory of their day — and could've changed the trajectory of their lives had they not acted so quickly.

The group was aboard a houseboat in Lake Powell, Utah, when they heard a loud explosion 45 minutes after boarding, one family member told KSL TV.

"We heard a big boom," Maddy Tolman told the publication. "Not knowing what it was, we went to investigate. We found the motor on the houseboat had exploded, and caught on fire."

Tolman said there were just 5 to 10 minutes between when the motor exploded and when the whole houseboat became engulfed in flames.

Video captured by onlooker Tyler Hutchinson shows the boat heavily ablaze, sending plumes of black smoke into the sky.

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Hutchinson told Storyful he took a Jet Ski to the scene near Glen Canyon National Park after noticing the smoke and hearing multiple explosions. Upon arrival, he said there were flames reaching about 20 feet high.

All 25 family members — including a mother and her 2-month-old baby, two toddlers and multiple elementary-aged kids — jumped into the lake to safety. KSL TV said some grabbed lifejackets, but others had to float.

The family said good Samaritans rushed to them on boats, which the family swam to to get to safety, all unharmed.

"Luckily, no one was hospitalized. No one walked away with any injuries," Tolman told KSL TV. "We're grateful to be alive and grateful for those who saved our loved ones by stopping to scoop us out of the water."

The houseboat completely burned and sank, and authorities are investigating the cause.