SHELTON - Police say three men are in critical condition tonight after a house explosion in Shelton.

The explosion happened yesterday afternoon on Wopowog Trail, in the area of Pine Rock Park.

Authorities say two Pioneer Gas Company employees were badly burned, as was the brother of Shelton Mayor Mark Lauretti. They mayor?s brother was at the site to talk with the workers.

Investigators say a propane leak may have caused the explosion. Connecticut residents are being warned to let the experts handle the tanks at their homes.