A natural gas leak in a townhome Tuesday afternoon caused the evacuation of adjoining units, according to the fire department. The leak at 1807 Robin Way was reported at 2:30 p.m., Appleton Fire Department Battalion Chief Ethan Kroll told USA TODAY NETWORK-Wisconsin. The first firefighters to arrive confirmed a smell of gas and meter readings on the outside of the building. They shut off gas to the unit and evacuated adjoining units. Kroll did not know how many people were evacuated. They then ventilated the building and, once We Energies arrived and the gas level came down, went into the home. The cause was determined to be a cracked valve going to the water heater, he said.