Three National Grid workers were injured Friday after an exploded, officials say.

The incident happened on Union Avenue and Hewes Street around 1 a.m.

Police say they received a call that there had been an explosion after three workers were fixing a gas leak in the area. 

The workers suffered minor burns to their faces and arms and were taken to Cornell Medical Center.

A Representative from The National Grid says there was a spark and then an explosion when the workers were excavating and digging in the street.

Two of the workers were treated and released while one worker is being held for observation.

The National Grid says it is investigating to see what caused this incident.