May Six Word Photo Story Challenge: “Water” — Smooth, calm, and inviting. But deadly. The River Wharfe in Yorkshire, England, is a picture-postcard idyllic waterway in some places. It has inviting pebbled beaches leading down into 30-metre (about 100 feet) wide stretches of water, tranquil enough for safe swimming — a magnet for families and picnickers every summer. At 65 miles long, the Wharfe…