The computerized voice emanating from the white motor home <a href=”https://www.cnn.com/2020/12/25/us/nashville-explosion-witnesses/index.html” target=”_blank”>offered a terrifying warning</a>: “This vehicle will explode in 15 minutes.”

The voice repeated the message, counting down as the minutes passed.

As the countdown continued, six police officers who heard those warnings sprang into action, helping residents in