Windsor fire officials say a fire at Staples caused $1.5 million worth of damage.

The blaze broke out at the office supply store at 7126 Tecumseh Road East on Wednesday afternoon.  

The investigation by the Ontario Fire Marshall’s office concluded on Thursday.

Officials say the fire was caused by an electrical power bar failure.

The flames spread after two volt lithium batteries nearby exploded.

Officials report many office supplies were damaged by smoke and water, and they fear the damage total could climb even higher than $1.5 million.

Windsor Deputy Fire Chief Andrea DeJong tells CTV News it initially appeared as though arson was suspected. However, a store security camera revealed exactly what happened, and the fire is listed as accidental.