Henric Östmark says that the big explosion is similar to the ones he has seen before.
- If you have a major explosion or detonation, this is what it looks like. It became a mushroom, which I saw people think was from a nuclear weapon. But if it's a bigger explosion, you get this type of vomit and the cloud looks like that, he says.
According to the Lebanese authorities, the explosion was caused by ammonium nitrate, a substance that is used for artificial fertilizers, among other things.
In the video, you can see Henric Östmark explain how the explosion looks like it happened.