The call came in around 8 a.m. Sunday.
Photos from one of the responding crews show water and smoke inside the building.
The photos were taken inside the sub-level storage area.
Firefighters say the fire started in a small storage unit where old sports equipment is stored.
The sprinklers immediately turned on. Not a lot of damage was reported.
There was a lot of smoke when firefighters arrived on the scene.
Fire crews used fans to clear the smoke from the building.
It's not clear what may have sparked the fire.
No events at the Toyota Center will be impacted because of the fire.