It really doesn't take much to cause an accident. On a mid week run last week, I was plodding along doing a few laps on a track. There was a LAX or soccer frame net in the middle lanes. I was running the middle lanes and going around the frame. On the 3rd lap my phone vibrated about 20 yards from the frame. I started walking and unlocking the phone. You know where this is headed. Next thing I know something is beaning me in the forehead. Hit that thing square. One step to either side and I would have missed it. Luckily, I had a billed cap on that softened the blow. More importantly, there wasn't anyone else doing laps to film it and make me an internet celebrity.
You have to do all you can to put yourself in safe situations. Even that might not be enough.