The Michigan city has lost half its population since 1960. A digital tool to improve collaboration is helping communities manage their abandoned properties.

The Oklahoma city joins winners from Italy and Colombia in what Michael Bloomberg calls "the best" examples of civic engagement.

Commentary: Tulsa, Oklahoma Mayor G.T. Bynum says the city's Urban Data Pioneers program is creating progress around policy areas like housing, public health and education.

Three winners will be selected in May for outstanding ideas to solve public challenges that can be adopted by other communities around the world.

The contest, which will award 00,000 in funding for creative technology ideas, has now ended its application period.