CLEVELAND -- A third "pothole killer" hit the streets of Cleveland on Tuesday.

The unit arrived last Friday and started repairing craters this week in the area of East 156th Lakeshore to Calcutta, according to the Mayor's press assistant.

The first two units have now moved to West 73rd from Dennison to Madison and East 147th from Glenndale to Miles. The city hired an outside company called Pothole Killers to help with the massive pothole problem this winter and spring.

The self-contained truck works by filling each hole with a mixture of asphalt and gravel to make a permanent patch. On an average day, the "pothole killer" can lay down up to 12 tons of asphalt -- compared to the city's eight tons.

The city estimates that it could take about two months for the machines to reach all the streets in need.