Seven people have died in Indiana house fires during a two-day period this week, and national fire officials are urging homeowners to replace outdated smoke detectors as a precaution.

A fire in Wabash County killed three teenagers Sunday. In LaGrange County, a 49-year-old man died in a fire the same day. Two people died Monday in a fire in Brownsburg, northwest of Indianapolis. That same day, an 80-year-old Evansville woman died in a fire.

The fires all remain under investigation.

The seven deaths account for a quarter of the statewide total for all of 2008, the most recent data available, according to the Indiana Department of Homeland Security. In previous years the state has seen about 40 fire deaths annually.

“One death is too much,” said Tom Olshanski, spokesman for the U.S. Fire Administration.

National statistics indicate more than half of all fire deaths occur in homes where smoke detectors were either not installed or not working property, Olshanksi said.

While investigators are still trying to determine whether smoke detectors were working – or even present – in this week’s deadly blazes, Olshanski urges residents to take precautions. Any smoke detector installed before July 2000 should be replaced, regardless of whether it’s currently working.

The life span for smoke detectors is 10 years because of intricate parts that deteriorate over time, Olshanski said.

“They will wear down by just being always at the ready,” he said.

A smoke alarm should have a manufacturer’s date on it indicating its age. If it does not, that’s another sign the device is too old and should be replaced, he said.

Many residents properly put new batteries in their detectors but neglect to check how old the devices are, Olshanski said.

About 3,500 people die in fires nationwide every year, according to the U.S. Fire Administration.

That averages to about nine or 10 deaths a day.

Additionally, about 25,000 people are injured in fires every year.

In addition to replacing smoke detector batteries at least once a year, fire safety officials urge residents to test the smoke detector monthly by pushing the test button on the device.

“Smoke alarms are like putting a firefighter on duty in your home 24 hours a day, seven days a week,” Olshanski said.

According to firefighters in LaGrange and Wabash counties, it’s unclear whether the homes where the fatal fires occurred had smoke detectors.

The LaGrange home was so severely damaged investigators are not sure whether they will be able to find a smoke detector, if there was one.

In Brownsburg, firefighters who responded to the fatal blaze did not hear smoke alarms sounding and could not find one in the home.

It was unclear Wednesday whether smoke detectors were in the Evansville home.

habrams@jg.net

The Associated Press contributed to this story.