WEST CHESTER, Ohio  — A fire broke out overnight at an apartment complex in West Chester.

The fire started around 1 a.m. Sunday at the Highlands of West Chester on Fountains Boulevard. When firefighters with West Chester Fire Department responded, the assistant fire chief said the fire was located on the second floor and flames were extending into the roof.

Initially, there were reports a man was trapped inside the building. Fire crews went to rescue him, but firefighters said the man walked out on his own. He refused medical attention.

More crews from other fire departments were called in to help battle the blaze.

At least two units were damaged in the fire, but it is currently unclear how many people are displaced.

"I don't have an estimate on damage. There are 8 units in the building that is involved at least two units are involved in actually fire damage," West Chester Assistant Fire Chief David Pickering said.

Pickering said crews are assessing the other units to make sure they are safe before residents can return home.

No firefighters were injured.

The Butler County Fire Investigation is still working to figure out how the fire started.

This is a developing story and will be updated when more information becomes available.