A ruptured gas line summoned Albany firefighters to a residential construction site near the intersection of Water Avenue and Hill Street on Wednesday afternoon. A worker struck the 2-inch high pressure line at about 1:50 p.m. with his excavator while digging a hole to place a street lamp. The leak rushing from the ground under the excavator could be heard hissing from several yards away. Because the leak was not filling an enclosed space, and because light winds dissipated the gas, Albany Fire Lt. Mark Bernt said there was no immediate danger to the public.