Nearly 100 firefighters were called to the building located between Harwood and Shepard streets in Rochester shortly after 4:00 a.m. Wednesday. There were no reports of major injuries but 12 apartment units had to be evacuated.

Crews are on the scene of a four-alarm fire at an apartment building on Monroe Avenue in Rochester Wednesday morning. The chief of the Rochester Fire Department is calling the blaze "somewhat suspicious."

Nearly 100 firefighters were called to the building located between Harwood and Shepard streets shortly after 4:00 a.m.

The blaze is now under control, but flames could be seen shooting from the back of the building.

The building has 18 apartments, 12 of which were occupied at the time of fire.

Flames spread to both staircases in the building, so residents had to use fire escapes and windows to escape, according to Chief Will Jackson. He says everyone inside made it out safely, but one person was taken to the hospital for minor smoke inhalation. One firefighter was rescued after a mayday call and another suffered minor burns.

The cause of the fire is still under investigation, but Jackson says, "at this time it's somewhat suspicious in nature."

Jackson believes the building may be salvageable.

Monroe Avenue is shut down at Shepard Street to the I-490 on-ramp.

This is a developing story. Please check back for updates.