Melisa Swearingen woke up early on Sunday morning as a tornado bore down on her home in the northwestern corner of Arkansas. As she raced down the stairs with her toddler, she looked out the window and saw a 40-foot tree falling toward the house.

“The whole house was shaking like a roller coaster,” Ms. Swearingen said in an interview outside her home. “I thought, This was it.”

But the tree smashed through a room above the family’s garage, giving her time to gather her 7-year-old son. As another tree crushed the other side of the home, she, her husband and their children huddled in a first-floor bedroom. “I thought the house would be torn open and we’d get suctioned up,” Ms. Swearingen, 35, said.

Nearby, Byron Copeland, 38, had sent his wife, their three children and the family dogs to the basement, while he monitored the storm. Then came the terrifying booms of exploding electrical transformers. “I ran toward the basement like a little girl,” Mr. Copeland said. As they waited for the weather to pass, he said, the family sang the lullaby “Jesus Loves Me.”

The Swearingens and the Copelands were among the millions of families whose lives were upended by the rash of tornadoes that ravaged parts of Arkansas, Oklahoma, Texas and Kentucky over Memorial Day weekend. At least 23 people were killed, including eight people in Arkansas.