The victim's name has not been released.
Fire broke out in the three-story apartment building shortly after 2 a.m. Firefighters also found one adult and one child calling for help from a third-story window.
Crews rescued the two, but not all of the building's 11 residents were so fortunate.
"We do have a single victim found inside the apartment building," Coroner Mike Norris said.
The fire burned inside the building for nearly three hours.
"A lot of times you'll find void spaces and hollow spaces where the fire can get into, which makes it very difficult to fight the fire and certainly it's taken a little bit longer because of that," Public Information Officer Roger Kohr said.
While the state police fire marshal has not found the source of the fire, he has been able to rule some things out.
"We went through and looked through a bunch of the wiring and we can't find anything significant with the wiring. That doesn't mean it's not electrical, but we haven't found anything," Deputy Fire Marshal Michael Rugh said.
Tina Monaghan and her husband live on the building's first floor.
"At this point in time, it's just one giant swimming pool. The roofs have collapsed from the third to the second and now everything's running into our apartment," Monaghan said.
Monaghan said her apartment floor is covered in four inches of water, not to mention all the smoke damage and that's just the beginning.
"We have renters insurance, but it goes into effect the day after tomorrow. So it doesn't cover any damage sustained in the fire," Monaghan said.
But Monaghan said the important thing is that she, her husband and their two children made it out alive.