Phoenix firefighters responded to the popular home improvement chain on Tuesday at 10 a.m.
Footage from FOX 10 showed first responders arriving at the store and begin assessing the situation.
Firefighters said the man was an employee and was working in an electrical room at the back of the store when the explosion occurred.
Crews said that the unidentified victim had “significant burns to his face and hands” following the unexpected explosion.
Authorities said the victim was transported to the hospital where he is in critical condition.
The store closed as firefighters worked to stop the fire from spreading throughout the busy store. Eventually, the fire was contained and the store reopened.
Firefighters worked to stop the fire from spreading throughout the store.
Authorities said no one else was injured during the incident and that the cause of the explosion is under investigation.