Firefighters are responding to reports of an explosion and fire at an apartment balcony in Cabbagetown that may have been caused by an e-bike battery.Crews were called to the 17th floor of a building on Carlton Street near Sherbourne Street around 9 a.m. on Wednesday.Toronto Fire says an e-bike battery was involved but it is not clear if it was the initial cause of the fire.No injuries have been reported.The occupants of the impacted apartment were evacuated from the unit, which was also damaged from the fire.