A huge, mysterious bright light shot across the US sky overnight – and it's not clear what it was.
The stunning flash startled drivers and the explosion was enough to rattle the walls of people's homes, according to residents.
Official weather agencies say the phenomenon can't be explained by the thunder and lightning. Instead, it's most likely that the flash was the result of a meteor entering the atmosphere, but that hasn't yet been confirmed.
Some around southeast Michigan reported that alongside the flash they felt buildings shake and pictures even fell off the wall. The flash and the disturbance came around 8.15pm local time, affecting cities around the Great Lakes like Detroit, Ann Arbor and Flint.
The flash was also seen across the sky in neighbouring states, local reports said.
Police were forced to warn residents that the flash hadn't happened in their town and that there was no need to call 911.
The National Weather Service confirmed that the flash wasn't thunder or lightning. But it couldn't say for sure what it was, it said.
"After reviewing several observational datasets, the NWS can confirm the flash and boom was NOT thunder or lightning, but instead a likely meteor," NWS Detroit posted on Twitter. "We continue to monitor feeds from astronomical agencies for official confirmation of a meteor."
While organisations like Nasa track large rocks that could collide with Earth, it's much more difficult to track smaller ones, meaning that they can fly into the atmosphere without any warning. Their small size also makes them far less dangerous, but both the flash and any debris that makes it down to Earth can be spectacular when it arrives.