Fireworks may look like simple explosions in the night sky, but the science behind them is surprisingly complex. Their origins date back more than 2,000 years to China, where early experiments with gunpowder eventually evolved into modern displays.

A fireworks-loaded trailer erupted in flames on Interstate 75 in Tennessee Saturday night, sending pyrotechnics across the roadway and forcing a shutdown.

The trailer carrying fireworks that caught on fire on I-75 Saturday had multiple safety violations and could have had "far more serious consequences," said the Tennessee Highway Patrol.