WSVN -- The motto is simple: First in, last out -- first into the flames, the heat, the darkness.
Mike Moser: "Unfortunately what we do is a very dangerous profession."
But firefighters have protection -- each other and their gear -- in case something goes wrong.
This is called a PASS device -- every firefighter wears one, and if someone goes down, or is trapped in a blaze, the device sounds the alarm to let everyone know a firefighter needs help, and quickly.
Mike Moser: "There's no sound that mimics it. There is no mistaking a pass alarm, and when we hear that we instantly react."
Patrick Fraser: "PASS stands for Personal Alert Safety Systems, they are really simple: if a firefighter stops moving for 20 or 30 seconds, this goes off. You can hear it two blocks away. It lets everyone know a firefighter is in danger inside a building and to go get them. But, when they fail to sound, when they're silent, a firefighter can die."
Laura Morrison: "If it had gone off, they would have gotten him out in the first two minutes, and he was so close to the door. He would still be here today."
Laura's husband Robert was killed when his PASS device was not heard by rescuers in St. Louis. No-one knew he was lying near a door, dying.
Investigators tested his device, including dunking it in water.
Look what happened when they pry open the supposedly waterproof box.
And, sadly, it's not the only time the devices have not alerted other firefighters there was a problem.
7 News went through reports from the National Institute for Occupational Safety and Health, or NIOSH, and found seven firefighter deaths in which their PASS alarms weren't heard. Firefighters dying in the line of duty in Texas, Missouri, New York, New Jersey, Tennessee and Florida.
The news does not surprise Eric Schmidt who says he first warned his bosses at NIOSH about the potential trouble with the alarms in 2000, but they ignored him and firefighters continued to die.
Eric Schmidt: "I think the results are that additional firefighters did not have the chance to survive because possibly some of these PASS devices did not sound or perform the way they should have performed."
But now the federal government is investigating the devices -- and their findings are frightening.
Nelson Bryner: "We discovered that as they heated up, the sound generated by the alarm emitter actually decreased."
Nelson Bryner led a team of researchers who put the PASS devices at the same temperature firefighters face -- 300 to 350 degrees.
Their conclusion -- when they get hot or wet, the device firefighters are depending on is not always dependable.
Nelson Bryner: "The firefighters need to be aware that when they enter that high-temperature environment the current version of the PASS device may not provide that level of protection that they might have assumed was there in the past."
For South Florida firefighters it's troubling news.
Mike Moser: "I think it should concern every firefighter that a study has come out that says a piece of equipment that is used to protect them may be faulty."
The National Fire Protection Association has issued new standards to make the PASS devices more reliable. But so far, those standards have not been implemented. And the devices -- at a cost of $4,000 each -- have not been replaced.
In some departments, like Coral Springs, they have installed back-up devices to alert supervisors in case a PASS device fails.
Assistant Chief Frank Babinec: "I don't ever think a firefighter should ever die in vain. If a tragedy does happen it's important that we learn from that and figure out how to prevent it in the future."
But sadly, the men and women who love to be the first in were not the first to know their PASS device might not save their life.
Laura Morrison: "He would still be here today. I know he would if something had been done about it when it was first found out about. I can't tell you how many firemen still do not know that their PASS device could not work."
Hopefully all firefighters will know, and we will see the last of a firefighter scene like this with this cause for alarm.
Even critics know these devices usually work and have saved hundreds of firefighters.
And all agree firefighters should keep wearing them until improved devices are available.