Crews responded to the report of a gas leak at Enfield Children Development Center on South Road in Enfield on Friday morning and did not find any hazardous levels.
A teacher smelled gas and called 911. before 7 a.m.
About 20 children were at the town-run daycare at the time.
No one was injured. The daycare was evacuated and the children were brought to the Mark Twain housing complex.
Parents have been notified and officials said the scene is secure.
Propane heats the complex and a contractor determined that the tanks were empty. When the tanks empty, they emit an odor, officials said.
The tanks have been filled and the children will be brought back to the daycare at noon.