This story first appeared on the ProPublica website.This story was co-published with PBS Frontline.
In the spring of 2008, AT&T was racing to roll out a new cell phone network to deliver music, video and online games at faster speeds.
The network, known as 3G, was crucial to the company's fortunes. AT&T's cell service had been criticized by customers for its propensity to drop calls, a problem compounded when the company became the sole carrier for the iPhone.
Jay Guilford was a tiny but vital cog in the carrier's plans.
On a clear evening in May, Guilford was dangling, 150 feet in the air, from a cell tower in southwest Indiana. He had been sent aloft to take pictures of AT&T antennas soon to be replaced by 3G equipment.