Looped Stem!

I have just re potted 3 seedlings as they were in clear plastic yoghurt pots and I could see the roots. (. They have only grown one true set of leaf's.) When I checked on them today one of them has grown a loop, I assume it must have fallen over. Would it be best to cover it with soil and let it become part of the root system or try to straighten it out? They weren't leggy so I'm not sure how it happened. Anyone had any similar problems?

If it's otherwise healthy I wouldn't mess with it .

as unga bunga said, leave well alone if healthy, you can put more soil in the pots to cover the stem once its grown a bit, it will grow roots on the burried stem