This article is the first part in a series on smart cities. See more from Christine Wong.

Smart cities are coming under siege.

In Songdo, South Korea, clusters of concrete high-rises sit empty, waiting for an influx of foreign workers that hasn’t materialized. The $40 billion smart city, which was to be completed last year, is only 70 percent finished. Just 100,000 people live in Songdo so far, well short of its target population of 300,000.

Read more