HOUSTON – It’s a job where a quick response can mean the difference between life and death.

It’s why Houston firefighters says they’re so concerned about the age and condition of the city’s fire trucks.

“Is this a problem that’s putting people’s lives in danger?” KHOU 11 Investigates asked Marty Lancton, president of the Houston Professional Fire Fighters Association.

“I believe so,” said Lancton. “Yes.”

Firefighters say more and more they’re not just battling flames, but also their own aging equipment when the alarm sounds.

“It’s not a question of if, it’s a question of when something catastrophic will happen,” said Lancton. “I mean somebody dies.”

That’s because broken trucks can slow firefighters’ response to an emergency.

And it’s not tough to see how big of a problem broken engines and ladder trucks are.

On a recent visit to the city’s repair facility, fire trucks sat in rows waiting to be repaired.

Work requests obtained by KHOU 11 Investigates confirm firefighters’ complaints that trucks are repeatedly written-up for the same recurring issues.

Those included everything from brake and engine problems to pumps leaking water.

All of it is a big concern to the city’s new fire chief.

“When we’re putting firefighters at the end of a fire hose, in a hazard zone, we have to know that that engine is reliable, that’s it’s going to pump water reliably, that it’s going to stay in service and that it’s going to be able to function as we expect it,” said Pena.

“Do you believe they’re reliable right now?” KHOU 11 Investigates asked Pena.

“Well…I can’t guarantee that,” the chief responded.

The city aims to replace so-called “front-line” fire trucks every 10 years, but an analysis by KHOU 11 Investigates found that’s not always happening.

Records show more than one out of every four of Houston’s front-line engines are older than 10 years. Nine of those engines are more than 15 years old.

And ladder trucks are even worse.

A city inventory shows nearly 40 percent of front-line ladder and tower trucks are a decade or older.

That includes three trucks that are more than 15 years old.

Firefighters say much like your car at home, the older the truck, the more likely you are to have a breakdown.

“As a truck ages, how can you say with all certainty that something’s not going to fail?” Pena explained. “I mean all the parts are 15-20 years old…so it is a concern.”

In fact, last summer consultants hired by the city found that fire trucks were out-of-service 17 times for more than six hours in June.

The same study found that in the first 11 days of July, trucks were out of service 13 times for more than six hours.

Referring to the problem, the consultants wrote, “Out of service apparatus means that firefighters do not have the proper vehicle to deliver service to their customers.”

HFD says when a fire truck breaks down firefighters are either moved into an older “reserve” unit, or into what’s called a “manpower unit.”

A manpower unit is basically just an SUV. It doesn’t carry water or firehose.

And if a manpower unit is the closest truck when a fire breaks out, it could be the first to show up at that fire.

The what-if’s hit close to Kanitta Diallo’s heart.

In 2012, a Houston firefighter’s quick response saved her twin daughters from a burning house.

“That could have been the difference between life and death,” said Diallo. “My twins were already passed out in the hallway and not breathing then. Any more seconds or whatever could have really cost them their lives.”

Now she’s worried that broken down, outdated equipment could have deadly results.

She believes the city needs to find a way to get newer, more reliable fire trucks on the road as soon as possible.

“You don’t want to look back and say ‘oh what if we did this,” said Diallo. “Don’t let someone lose their loved one because the fire department can’t get to them properly. Because I almost lost mine and that almost broke me down, so to imagine someone actually losing their family due to a fire because they can’t do what they need to do, I can only imagine how horrible that would be.”

Pena says updating the department’s fleet is a priority.

But the chief believes the price tag could run $10 million a year. That’s more than double what the city has been spending on new fire trucks.

Pena also estimates that investment would need to continue for at the next 10 years.

But as the city struggles with funding issues, getting that kind of earmark could be a struggle at city hall.

“People are demanding that you cut back and we are doing that,” Mayor Sylvester Turner told KHOU 11 Investigates. “They’re demanding that we operated under a revenue cap and we are doing that. But having said that, there are trade-offs.”

While Turner agrees the equipment is needed, he says it’s a matter of prioritizing spending.

“I hope it doesn't get to the point where somebody is injured or somebody suffers or somebody is killed before the light goes on in everybody's head,” said Turner. “I promise the people of this city, I will squeeze as much as I can out of the dollars that taxpayers are giving to us as the city of

Houston. But there will come a point in time that no matter how hard I squeeze, there is nothing coming out. And we’re getting close to that point in this city.” This is not the first time the city has dealt with the issue of aging fire trucks.

In the mid 1990’s, HFD made national news after the same broken fire truck was sent to two different deadly fires days apart.

After that, the city spent millions to buy new fire trucks.

Now, nearly 20 years later, some of those same trucks are still being used each day here in Houston.