Gov. Jay Nixon said rescuers had found at least five families still alive under the rubble.

But many had far grimmer tales. Mark Stepp, whose house was destroyed, spent the day digging out homes. Beneath one, he said, he found the body of a young girl — a discovery that left him vomiting at the street’s edge. “I found a little girl,” he said, pacing and frantically puffing on a cigarette. “I’m so freaked out.”

Of the 183 patients at St. John’s on Sunday night, five died as a result of the tornado, a hospital official said. All had been in critical condition before the storm, he said.

The rest — some of them injured in the storm, adding to the problems that put them in the hospital in the first place — were sent to other hospitals in three states. In the confusion of the day, some patients’ family members found themselves driving from hospital to hospital, looking and worrying.

“Do they have a list? Do they have a list?” Kimberly Cain called out, as she and her son arrived at an emergency command post. She was searching for her husband, who had been on the fifth floor of St. John’s when she last heard from him. There were no lists, she was told, or at least none that anyone knew of. There had not been time.

A tornado warning was issued in Joplin a relatively lengthy 24 minutes before the tornado struck, officials say, though workers at St. John’s said the warning system in their building had given far less time. From the moment that alarm went off, though, they worked through the procedures designed to protect patients and themselves. But they were quickly overwhelmed by the force of the tornado.