ABC iPad Factory Tour: 'Nightline' Teases Glimpse Into Foxconn Facility (VIDEO)

On Tuesday 21 at 11:35 p.m. (EST), ABC's Nightline will offer viewers an exclusive look at factory floors inside China's massive electronics manufacturing company Foxconn, where lines of silent workers speedily assemble Apple's hugely popular iDevices.

Host Bil Wier explores what he calls a "hidden corner of our world" and sheds light on the working day of employees at the city-sized Foxconn branches in the Chinese cities of Chengdu and Shenzen, as well as the controversies plaguing these and other factories where high-tech gadgets are assembled.

ABC on Monday released a 90-second teaser video ahead of Tuesday's Nightline segment.

(Check out the preview below, and visit ABC to read Bill Weir's overview of his visit to these locations.)

The Nightline segment features interviews with workers who travel long distances by bus for a chance to score a job assembling iPhones, iPads, MacBooks and other devices for, according to ACB, less that $1.50 per hour.

As China's largest exporter, only the government employs more people than Foxconn, and the company earns more revenue than their next 10 competitors combined. Apple may be their most famous customer, but Foxconn also churns out products for Sony, Dell, Hewlett-Packard, I.B.M., Motorola, Toshiba and other major brands, keeping the details of each production line wrapped in total secrecy. [...] In order to make gadgets like the Xbox, the PlayStation and the Amazon Kindle this campus employs 235,000 people, roughly the population of Orlando, Fla.

Weir's coverage for Nightline also examines controversies, such as factory explosions and a string of worker suicides, that have plagued Foxconn since 2010 and have recently prompted Apple to take action.

Stressful and potentially dangerous working conditions inside Foxconn plants were detailed last month in a two-part expose by the New York Times and a broadcast segment of This American Life. Hundreds of thousands of Apple customers and concerned individuals signed petitions demanding Apple take action to improve working conditions for Chinese factory employees in the company's supply chain. Signers presented the petitions to Apple in early February.

Apple announced on February 13 that it had joined the Fair Labor Association to launch an investigation into working conditions at Foxconn and other assembly facilities. Although the initial word from FLA President Auret van Heerden was that conditions in Foxconn's Chengdu and Shenzen facilities appeared better than average, as reported by Reuters, Heerden soon said that inspectors were "finding tons of issues" at the Shenzen plant, according to a Bloomberg interview published on February 17. (Full details from the FLA report will be published sometime in the next few weeks.) The same day, Foxconn announced that it had increased worker salaries by as much as 25 percent in February, brining the monthly salary of junior-level workers in Shenzen to $290, per Reuters.

Ahead of Nightline's airing of its tour of Foxconn plants, Forbes has pointed out the close ties between ABC and Apple, raising the possibility of a conflict of interest.

"ABC’s parent company is Disney Corporation. The top dog at Disney, CEO Bob Iger, sits on Apple’s Board," writes Forbes' E.D. Kain. "Meanwhile, the late Steve Jobs (and now his family) are the biggest individual shareholders of Disney."

WATCH: [via ABC News]