Black smoke was seen rising form the Cancer Institute around 2:30 p.m. Officials say construction workers were on the roof at the same time some of their materials caught fire.
No one was injured and the building has been evacuated.
Firefighters have pumped water on the blaze.
FIRE: St. Josephs Cancer Institute, 3001 West Doctor Martin Luther King Junior Boulevard, per @TampaFireRescue pic.twitter.com/5QAR76Ty3G
— HCSO (@HCSOSheriff) February 26, 2015