DETROIT -

Firefighters were called to a two-alarm fire at a vacant apartment building on Detroit's east side Thursday night.

The fire in the 5000 block of Harding Street spread to an occupied house. 

At least one ladder and three engines were called to the scene.

It's unclear if anyone was injured in this fire.

Investigators suspect the fire was deliberately set.

Stay with Local 4 News and Clickondetroit.com for more on this developing story.