Fearful residents along the mid-Atlantic coast called local authorities on Sunday night after witnessing a giant fireball light up the night sky at around 9:45 p.m.

Initially, residents called 911, believing the fireball was a rocket, comet or even a UFO according to The Washington Post. Residents reported seeing green, blue and orange in the sky as well as the sound of an explosion. According to the Post, witnesses described the lights as a “fireball” and “heading downward.”

People also began calling the National Weather Service in search of clues as to what transpired during the night. The local offices, whose phones were ringing off the hook, referred callers to the National Weather Service headquarters in Boulder, Colo.

In a statement released that night, the National Weather Service indicated that the cause was not yet known, but no damage was caused by the mysterious lights.

“Numerous reports have been called in to this office and into local law enforcement concerning what appeared to be flashes of light in the sky over the Suffolk/Virginia Beach area,” the statement said. “We are confident in saying that this was not lightning … and have been in contact with military and other government agencies to determine the cause. So far … we have not seen or heard of any damage from this and will continue to inquire as to the cause.”

Although the National Weather Service did not understand the cause of the bright lights, Naval Observatory Spokesman Geoff Chester told CNN that the morning after the sightings of lights, he was able to track the path of Russian rocket debris over North Carolina during the time of the sightings.

In an interview with the Post, Chester indicated, “I’m convinced that it was the second-stage booster of a Russian Soyuz rocket re-entering the atmosphere.”

The Russian rocket, which was launched on Thursday from Kazakhstan, was orbiting the earth until its batteries died on Sunday. Experts predicted a 12-hour window, Sunday from 6 a.m. to 6 p.m., during which the booster re-entered the atmosphere over the east coast.

The booster, moving 5 miles per second, ionized the atmospheric molecules, causing the blue and green colors during re-entry. The loud explosion heard by some citizens was the sonic boom produced by the booster’s rupturing fuel tank, according to the Post.

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