GRAND RAPIDS (WZZM) -- Firefighters are looking into the cause of an early morning fire at a northeast Grand Rapids business.
It happened around 3:30 a.m. Friday at CrossFit Luminary on Maryland Avenue near Oak Industrial Drive NE.
Firefighters say a passerby spotted the fire and called 911.
Crews they thick smoke was coming from the building when they arrived. They were able to put the fire out within 30 minutes.
Firefighters suspect the fire may have started in an office or storage area.
No one was in the building at the time of the fire.