Missing 75-year-old woman, Lucy Thompson, last seen near Wichita River Walk wearing a blue floral dress and light sweater.

My grandmother, Lucy Thompson, has been missing since yesterday afternoon. She was last spotted walking near the Wichita River Walk around 4 PM. She is 75 years old, about 5'5" tall, with short gray hair and was wearing a blue floral dress with a light sweater. We're really worried about her, and any information would be greatly appreciated.