Betsy Williams and her wife, Kim Madlom, were sleeping soundly Christmas morning in their Nashville apartment, the hum of a white-noise machine blocking out the usual sounds of the city. Then, they were awakened predawn by what sounded like automatic gunfire.

The shots came staccato, at least three rounds. They called 911. Police began combing the area, near the city’s honky-tonk bars. Only in retrospect would the couple wonder if they were actual shots being fired, or if they were sounds from an amplified recording.

Williams looked out her third-floor window, and on the street below she saw a white, clean-looking, older-model recreational vehicle. She realized that the RV was the source of a new sound, a recorded warning.

At first, the message was that the vehicle had a bomb. Then, Williams said, the message was: “This vehicle will explode in 15 minutes. And then 14 minutes, and 13 minutes.”

Williams called 911 again. The couple were still in their pajamas, but at the 11-minute warning, they scooped up their cat and raced to their car, planning to drive across the river. The countdown was too ominous to ignore.

“That was the thing that made us decide to go,” Madlom said.

Williams, 64, a Georgia native, had lived in Nashville for 15 years, and she loved being in the center of the vibrant city, near the clubs where so many aspiring musicians sought stardom, and the popular Wildhorse Saloon and the historic Ryman Auditorium.

Williams owned a basement restaurant called the Melting Pot, and she lived above it, in her apartment with Madlom. Her son and her sister also lived in apartments in the building. The structure stretched 212 feet from Second Avenue to First Avenue, a fixture amid a normally bustling scene of country music lovers.

It had been a horrid year, with devastating tornadoes and the coronavirus pandemic, but the prospect of a quiet Christmas and the coming vaccine had given people much-needed hope. Now, as Williams and Madlom and their cat, Mavis, traveled in the car across the bridge to Nissan Stadium, they waited. The temperature hovered around 20 degrees.

Four minutes. Three minutes. Silence. They waited. They pondered the sound of gunfire and concluded that it was probably recorded.

“It was like it was being fired right next to your head almost,” Madlom said. “It was unrealistically loud in retrospect, and it was the exact same pattern all three times. Even when we were driving away, we were thinking those gunshots were recorded.”

Once the 15 minutes passed without an explosion, the couple decided the whole episode was a “sick prank,” Madlom said, and they headed back.

Unbeknown to them, the RV now was blaring a different message, according to a video later posted on social media that has not been independently verified by The Washington Post, warning: “This area must be evacuated now. If you can hear this message, evacuate now.”

The couple drove back across the river, crossing Korean War Veterans Memorial Bridge, and headed toward Second Avenue, nearing the intersection close to their home. Suddenly, they saw a plume of smoke rising from where they lived.

“The thing blew up right before we got to that intersection,” Williams said. “The fireball from that explosion just rose.” She turned down First Avenue, at the rear of her property, “and all of the windows were blown out of the back. I mean, it was just chaos.”

Along the block, buildings were smoky silhouettes, blasted through with huge holes, Williams said. She owned a vacation rental business in the same area, but no one had booked Christmas Eve and the unit was empty. Guests were scheduled to arrive on Christmas Day.

“We’re probably never going to get our things back,” Madlom said. “We can see from the images down there that we have structural damage to our building. After 15 years, we have a lot of things we’d like to get back. But they’re just things. We’re all okay. We’re very blessed to have people who will help in any way we need it.”

Looking at her apartment, filled with debris and the windows blown out, Williams was relieved that they had heeded the warning coming from the loudspeaker on the RV and left the area. She was also relieved that they had not returned to the apartment before the blast.

“If we had not left, we would have either been severely injured or dead,” Williams said. “We would have been blown way back. And if we hadn’t been killed by flying debris, we would have been impaled or something. We would have been knocked senseless up against the wall.”

Williams feared that she and her city had lost so much. All around her was smoke, stench and the tangle of metal. Then she looked up at the apartment where her family had planned to exchange presents.

In the window, she noticed, the lights were still shining on the Christmas tree.

Julie Tate contributed to this report.