A state investigation has found that one National Grid worker was to blame for two separate home explosions on Long Island, one of which injured more than 20 people.

A New York Public Service Commission report found that the worker, who was not identified, failed to properly seal a gas line at a Brentwood home that was undergoing renovations back in 2011. The Fourth Street home was completely demolished when it exploded on Easter Sunday. A total of 21 people were injured.

The PSC report found that the same worker was linked to an explosion at a Central Islip condominium 15 months later. The report says the employee failed to follow proper safety procedures, and was never tested for drugs or alcohol after the explosion. No one was injured in the Central Islip blast.

National Grid tells News 12 Long Island that the employee is no longer with the company, but it wouldn't say if the employee quit or was fired.

The utility could face up to $6 million in fines from the PSC.

National Grid was expected to respond to the commission this week. However, News 12 has learned it has asked for an extention