Crews responded to Waterbury-Oxford Airport on Sunday morning for an incident at one of the fuel farm tanks.
Dispatchers confirmed fire crews were on the scene on Sunday morning.
Officials said the fuel farm is managed by Keystone, which is a fixed base operator at the airport.
Two employees of Gem Services, a contractor for Keystone, were performing routine maintenance on the tanks and were injured.
They were brought to Bridgeport Hospital.
Officials said the incident is under investigation by the CAA's fire department, local fire services, the state fire marshal, Connecticut State Police and OSHA.
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