MADISON, Wis. -- When a smoke alarm sounds in a home, will it be enough to wake everyone in the family?

Sounding The Alarm. .. Will Yours Kids Wake Up?

News 3 has learned that smoke alarms can provide a false sense of security.

Most families rely upon them to wake all family members, no matter what time of the day or night, but they don't always accomplish that goal.

That's news to Assistant Fire Chief Ernesto Martinez.

Martinez and his wife MiMi Doyle said their children were very prepared for a fire and were confident the children would awaken.

The family's home is 100 years old, but they just had a state-of-the-art hard-wired smoke alarm system installed three months ago.

He said he was sure the alarm would jolt everyone out of bed, if ever necessary.

Even Martinez and his wife are a bit concerned the shock of the alarm going off might traumatize their children. They agreed to try the alarm test hoping it would help other families learn about fire safety.

The children were not aware of the pending alarm test.

Once the house was quiet, Martinez set off the alarm.

It blared through the home like a siren, "beep, beep, beep."

But even as the first beeps screamed through the upstairs, 7-year-old Lily slept peacefully and 9-year-old Mason's door remained closed.

The alarm test function stopped automatically after about one minute, so Martinez restarted the test two more times, and still neither child woke up.

"I'm just amazed that neither one of the kids really woke up to it," said Martinez.

After about four minutes of the blaring alarm, a groggy Mason stumbled from his bedroom into the hallway, but then immediately returned to bed.

Seven minutes into the test Lilly stirs, sits up in her bed, and then goes back to sleep.

"I was shocked," exclaimed Doyle. "I thought for sure both kids would wake up, out of a sound sleep, and be totally confused and not recognize the alarm system and know what it meant."

"I was amazed how sound asleep she was," said Martinez. "There was no movement there, no eye movement until the very end when she started coming to, but by that time our house would have been engulfed."

Fire experts said survivability greatly decreases once three minutes has passed.

"Fire doubles in size every 30 seconds," said Martinez. "So you think about a waste basket fire, or a fire in the kitchen, the fact it doubles in size every 30 seconds -- to fill a room is really just a two to three minute process."

Martinez knows that fact all too well.

"I have to go to plan B, this doesn't really work," he said. "You know the whole purpose of having this alarm system installed in the house -- well it's not just for the kids, but primarily it's for them. We've talked about what to do, to feel the door and check if it's hot. We've reviewed all that stuff, but if they don't wake up it's all a moot point. I've got to do homework and find out what else we can do."

Chief Martinez was stunned to see for himself what researchers have known for sometime; that smoke alarms don't necessarily wake up children. The fact is not widely publicized.

The fine print on some smoke detectors warns that it may not wake up children.

News 3 checked three separate brands of smoke detectors and found that not one of them listed the warning.

Make A Plan

Fire education experts said it is very important for parents to know what their own children would do in the event of a fire.

They first suggest getting children familiar with how the alarm sounds.

Then, talk to the kids about what the family would do in the event of a fire.

Experts said families should develop a plan together, keeping in mind the smoke alarm might not wake everyone, and then practice the plan as a family.

Fire education experts say it is also important to practice at night.

"The other thing about practicing with the entire family, it really lets your children know that you're taking it seriously, that it's not something you're saying, 'Well if this ever happens, here's what you do, now we're done talking,'" said Community Education Officer Lori Wirth. "This puts the safety of the family center stage."

If you'd like to create your own fire education plan, but don't know where to start, News 3 and the Madison Fire Department have a step-by-step guide online.

Tuesday Night, Why Do Kids Sleep So Soundly?

Medical experts said there is a physiological reason why kids sleep through loud sounds like smoke alarms.

News 3 went to St. Mary's Sleep Lab in Madison to get some answers.

A 9-year-old girl provided News 3 with revealing insights in to why it is so hard to wake sleeping children and why, if they do, they are often confused.

"When the alarm goes off, odds are going to be higher they they're going to be in that stage of sleep that they're going to have a hard time awakening from," said Dr. Middleton.

"You really cannot count on a kid, of any young age, awakening and knowing what to do, let alone awakening as it turns out."

The results of the sleep study will amaze viewers and have already changed one family's emergency fire plan.

Plus, Tuesday night one Middleton family does its own smoke alarm test live on News 3 at Ten, The Update.