Still, on Saturday, she prepared Ro, her largest and gentlest horse, for a surprise. In the days leading up to her 91st birthday, Ona Kitt had told her family that she had one thing on her bucket list — to ride a horse one more time — and Ms. Early, a friend of one of her relatives, had promised to make it happen. The train derailment was not going to change that.

“In all this catastrophe, you get a half-hour,” Ms. Early said, her voice trailing off as she raised her hands toward the ceiling of her barn, where sunlight shone through the windows.

Nearly two dozen members of Ms. Kitt’s family filed into the barn, days after some of them had evacuated and begun arranging tests to make sure their water and homes were safe. Despite the stress, they had not entertained the possibility of missing a chance to surprise Aunt Ona and see her on a horse again on her birthday, evoking the years when she barrel raced and rode right up until she gave birth to twins. Life, they agreed, goes on.

With Ms. Early and Ro quietly standing in the center, a few of the men carefully helped Ms. Kitt onto the horse. As Ro began to walk in a circle, Ms. Kitt broke into a wide smile, waving her hand above her head like a pageant queen as her family whooped and cheered, filming her on their phones.

Beaming from a chair afterward, as she watched other relatives take turns trotting around the barn, Ms. Kitt summed up what the ride had meant, as her family forgot about the stress the community was experiencing.

“It felt,” she said, “like being young.”

Kitty Bennett contributed research.