interference, obstruction or wreck?

[shipwreck]

This is posted on another site also but am putting it here also to get more input.
Here's the scenario-- Runner on second. Hard hit up the middle to the right of the pitcher. Pitcher and shortstop both go for ball since it is hit sharply and either one may have a play. At the last split second, the pitcher snags the ball off the ground. At the same time there is a collision that involves the runner and the shortstop. What is this? Interference since if the pitcher hadn't gotten the ball the shortstop could of had a play? Obstruction since she didn't make the play and obstructed the runner? Or just call it a wreck and let the play go? Thanks, Dave