FOX 21 News, KQDS-DT

DULUTH - Duluth Police are investigating another suspected arson fire in Duluth. It's the fourth to hit the city in just the past four weeks.

It’s another week and another suspicious fire occurring in Duluth overnight. The latest fire happened early Tuesday morning in an unoccupied apartment building in West Duluth.

"The fire marshal's office within the Duluth Fire Department investigated the origin and cause and determined the fire to be of arson," said Todd Kuusisto, fire investigator with the Duluth Police Department.

It's the fourth suspected arson to happen in as many weeks and it's got neighbors asking why?

"It's scary to think that it's happening so regularly in Duluth, especially this year. You know, I have to wonder why. Is it just teenagers having fun or is it someone who's deranged," said Tia Werner, a concerned neighbor.

And this isn't the first time the neighborhood has been hit by this type of activity.

"It's twice now on either side of our house so I'm worried that what's going to keep them from actually setting something to fire that actually has people in it," said Werner.

Despite the rash of arson, fire investigators don't see any connection among them.

“I've been in contact with the Superior Fire Department and Police Department at this time we have no connection between the fires over in superior in Duluth,” said Kuusisto.

Kuusisto says finding a suspect or suspects can be difficult considering they rely on the burnt ruins left behind.

Kuusisto said, "We have to build that back together and we always hope that there's somebody out there in the neighborhood watching but unfortunately on a fire situation there's a lot of information that we don't get."

The best thing people can do is to report any suspicious behavior to police and remain vigilant.

Werner said, "Look for weird stuff, people lurking around that shouldn't. I mean we're pretty vigilant already just because of our kids but I guess we're going to be even more so now."