A large, fleeting flash of light that appeared in the darkened skies over the northwestern edge of metro Phoenix remains a mystery.
The ball of light that looked like an explosion was captured by a traffic camera on Interstate 17 around 4:45 a.m. Thursday and happened to broadcast by KSAZ-TV when the station showed footage of the roadway during a report on the morning's commute.
The two electric utilities that serve metro Phoenix say they didn't have any reports of electric transformer explosions.
Messages left for officials at nearby Luke Air Force Base weren't immediately returned Friday afternoon.
In 1997, dozens of people saw lights in a V-formation over Phoenix, a mystery that was captured on videotape and spurred calls for a government investigation.