A family says they'll never be the same, after a trip to Echo Bay at Lake Mead ended with their 11-year-old dead.

Initially, back on Thursday, authorities believed the young boy has drowned.

Now, the family has learned from the coroner's office that Joshua Murphy actually died from carbon monoxide poisoning.

Drowning is being called a "contributing factor".

In this case, the truth is making it that much harder for the family. What killed this young boy is something they never thought they had to worry about.

"We don't want other families to die. I've been crying and crying for two days now. I can't imagine this happening to anyone," said Tina Browning, the stepmother of the 11-year-old.

Browning tells us Murphy was visiting Las Vegas from his home in Montana.

She says Lake Mead seemed like a care-free getaway. The 11-year-old was splashing around next to the house boat they had rented.

Then came an alarming sight - the young boy was floating lifeless on the water's surface.

"You don't expect to go out on a family vacation and come home without your loved one."

The boy's older brother, frantically tried CPR, not knowing Murphy had inhaled carbon monoxide.

It's believed that he was playing near a cloud of exhaust that had come from the boat's generator.

"I'm devastated," said Browning. "Beware, please, of carbon monxide poisoning."

An invisible and odorless culprit that's causing nothing but grief for the family of this 11-year-old.

Sadly enough, park rangers at Lake Mead say fresh oxygen could've saved this boy's life within the first five minutes of him going unconscious.

Joshua Murphy's family tells us they plan on burying him back near his home in Montana.

Carbon monoxide can build up if there isn't a light breeze so experts say it's important to be very cautious.

The CDC says 500 Americans are killed each year from accidental carbon monoxide poisoning.

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