tps563200

I  laid out a board for the tps563200 and did not notice (even though I was aware of the warning) that I had inadvertently put the switch trace under the chip. I have to relay the board anyway because the trace is too narrow. when I turned the chip on (with a small load (50ma)) I was getting my 5v out but about a minute later the chip burned up. My guess is that the chip started oscillating because of the switch trace under the chip. Is that what you think? I also am laying the chip out on a two layer board. Do I have to have a three layer? I am currently using copper pours as recommended in the spec.