LOUISVILLE, Ky. (WDRB) -- A fire inside the Pebble Creek Apartments in Okolona kept firefighters busy on Tuesday afternoon.

“It did get into some of the upper second floor apartment units, but luckily it did not breach the fire wall and get to the other side of the apartment complex,” said Mike Allendorf, Fire Marshal with the Okolona Fire Department.

There were half a dozen fire departments helping, along with the Louisville Metro Arson Squad.

They sometimes get called to help investigate the cause of a fire. On Tuesday, it was determined the cause was an overheated bathroom fan.

Major Henry Ott has been with the department nearly 35 years and he says the Louisville Metro Arson Squad has been busy lately with apartment and house fires.

They've been called to three separate fires in the past 24 hours.

In January, Major Ott says they investigated 22 intentionally set fires.

“We've made arrests on three of those. We have two or three others that we plan to make an arrest on ,” said Major Henry Ott.

He calls that an average number that tends to go up in the summer.

They investigate about 300 set fires a year.

“We have a clearance rate of somewhere around 35 percent. The national average for cities our size is 17,” said Major Ott.

Investigators continue to look into a fire on South 18th street in the Russell neighborhood. The fire was set on January 9th. Major Ott says they have leads in the case.

“We know who we're looking for, it's just finding that person is the hard part,” said Major Ott.

Ott says when a fire ends, the investigation continues.

There are many unsolved cases that they're currently looking into, including one that hits close to home.

“The fire that killed Sgt. Craig Drury back in 1994,” said Major Ott.

Ott says he would love to see the arson squad find the person who set the fire, that killed the volunteer Highview firefighter.

They call this case a top priority for the arson squad.

“That's the one thing that's around my office all the time and when we get a chance we work on it. That's one that I really would like to resolve,” said Major Ott.

There are usually 10 people who make up the Louisville Metro Arson Squad.

Last year the arson squad was called out on 620 runs.

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