It's a long and storied tradition: not just Apple products catching fire in one way or another, but of portable devices in general. Now we have the first iPhone 4 incident, with the new iDevice igniting while hooked up to a PC with a USB cable.

For one it doesn't seem to be a battery issue. From the image acquired by BGR (above) it's clear that the device isn't going to be repaired. It also appears the owner was using the official Apple USB cable that shipped with the device. The customer took the device into an AT&T store in hopes of replacement.

According to BGR's AT&T source, an Apple Store indicated that it appears there was a defective iPhone 4 USB port involved. The source added that the customer's hand was slightly burned.

Interestingly, a commenter at the BGR post said he plugged in his iPhone 4, and a few minutes later saw his first ever “excess temperature” warning, and the iPhone entered safe mode as well.

Later, when he plugged it in to charge overnight, he saw it heat up significantly. It's unclear if this is a pattern yet, but it's something to think about.