Americans needing emergency service might not get timely help if they call from a cell phone.

A new Public Safety Answering Points survey shows 76 percent of calls to 911 are placed with wireless phones instead of a land-line, and 64 percent originate inside a building.  

But 54 percent of the managers and dispatchers who take these calls say the location information provided by cell phone companies are "regularly" inaccurate.  

Nearly half of the dispatchers admit 911 calls are "regularly mis-routed" because they're given the wrong location.