The Guelph Fire Department responded to reports of a fire at an apartment building early Saturday morning.

It happened around 12:10 a.m. at 80 Speedvale Avenue West.

Units from six stations responded, finding black smoke coming from the fourth floor of the building.

The fire was subsequently extinguished by an aggressive interior attack.

Fire damage was contained to the apartment, a media release said, but water damage to other units caused some tenants to be displaced until cleanup was done.

All other residents have been allowed back into the building.

One person was taken to Guelph General Hospital to be held overnight for observation.

The cause of the fire and damage estimates are still under investigation.