The tragic explosion at a iPad 2 polishing plant in Chengdu has already killed three and wounded dozens, and the closing of that facility could affect iPad 2 supply by up to 30%.

In the short term, iPad 2 supply is likely to get even worse, as Foxconn has just closed all of its polishing plants across China for investigation.

The unexpected explosion that rocked Foxconn’s Chengdu facility on Friday killing three has been blamed upon a build up of combustible dust at the iPad 2 polishing plant. As a two-week old report on factory worker conditions makes clear, though, the dangers of allowing such dust to build-up has been brought to the attention of Foxconn and Apple before.

A few hours ago, an explosion rocked Foxconn’s Chengdu manufacturing facility, which is one of the main producers of iPad 2s within China…. and it’s looking increasingly likely that the explosion might have occurred on the iPad 2 production line.