A $40 million prison sits in the desert north of Baghdad, empty. A $165 million children's hospital goes unused in the south. A $100 million wastewater treatment system in Fallujah has cost three times more than projected, yet sewage still runs through the streets. As the U.S. draws down in Iraq, it is leaving behind hundreds of abandoned or incomplete projects. More than $5 billion in U.S. taxpayer funds has been wasted on these projects - more than 10 percent of the $53.7 billion the US has spent on reconstruction in Iraq, according to audits from a U.S. watchdog agency. That amount is likely an underestimate, based on an analysis of more than 300 reports by auditors with the special inspector general for Iraq reconstruction. And it does not take into account security costs, which have run almost 17 percent for some projects. Even completed projects for the most part fell far short of original goals, according to an Associated Press review of hundreds of audits and investigations and visits to several sites. The reconstruction program in Iraq has been troubled since its birth shortly after the U.S.-led invasion in 2003. The U.S. was forced to scale back many projects even as they spiked in cost, sometimes to more than double or triple initial projections.