What do we know about what caused Saturday's dramatic explosion on the Kerch Bridge?
There are plenty of theories, not all of them are accurate.
Russia was quick to suggest this was a truck (lorry) bomb, but didn't say who orchestrated it.
The foreign ministry spokeswoman, Maria Zakharova, said Ukraine's ecstatic response showed its "terrorist nature" - yet stopped short of accusing Kyiv.
Security camera footage released on social media showed a truck - allegedly from the Russian city of Krasnodar, an hour's drive from the crossing - moving west across the bridge at the time of the explosion.
Russian officials named a 25-year old Krasnodar man, Samir Yusubov, as the owner of the truck, and said an older relative, Makhir Yusubov, was the driver.
But close examination of the footage seems to show that the truck had nothing to do with the explosion.