An early morning fire that forced dozens of people to flee from their Sharpsville apartment building is being investigated as an arson.

Firefighters were called out the Trail Blazer Building on West Ridge Avenue at around 2:30 a.m. Thursday.

Initial reports said some people were still inside as smoke filled the first floor. One resident told us that she woke up to find fire trucks arriving and rushed to escape from the building.

The fire was extinguished by 3 a.m. 

The Sharpsville Fire Department said the fire was contained to the first-floor hallway, but all 21 units that were occupied had to be evacuated.

They said there was no structural damage because of the fire, but there was substantial smoke damage.

No injuries were reported. 

The Red Cross was helping at least nine families that had become displaced at St. Bartholomew's Church on West Ridge Road. 

The cause of the fire is under investigation.