About 70 percent of 9-1-1 calls came from cell phones in 2014, and finding out where the calls came from required triangulation. A "USA Today" study showed that where information was compiled on the subject, many of the calls from cell phones did not include information allowing the caller to be located. Chances of getting as close as were higher in areas with more towers. But if a call was made from a large building, even that would not be enough to precisely locate the caller. New federal rules, which service providers helped with, require location information for 40 percent of calls by 2017 and 80 percent by 2021.