What happened here?

I was strolling along the beach and came across these glasses and two socks in the surf. The second sock was far enough away that it isn't in the photo.
A question popped into my head. What happened here? I hope nobody had drowned. Glasses and socks seem strange as the only things left behind.
It also crossed my mind that sometimes we end up asking ourselves that same question. Despite our best intentions and efforts, things happen. A bike on its side. Sometimes worse. Then the questions.
What happened here?
If we're lucky we're able to answer the question, continue to ride, and end up a little wiser.
Miles and smiles,
Dan