Fire officials say a lithium-ion battery inside a vacuum cleaner sparked a fire at an apartment complex Sunday afternoon in Gravenhurst.
According to the Town, the fire and smoke damage was isolated to one apartment unit at the Preston Way building.
Officials suspect the lithium-ion battery that powers the vacuum experienced a thermal runaway.
"In a nutshell, a thermal runaway is when a battery heats up uncontrollably," explained Deputy Chief Todd Clapp.
Officials say these types of incidents are behind a growing number of fires recently and warn lithium-ion batteries should never be stored in direct sunlight.
"Do not tamper with or modify batteries and follow manufacturers' instructions," the Town added.
Lithium-ion batteries can be found in various devices, including smartphones, laptops, cordless power tools, e-bikes, and other electronic devices.