I think it's something involving electricity due to the blue aura when the explosion happened. This video breaks the footage down and he says it's lightning. Plausible but I think definitely something with electricity is a factor. Also GIB released footage of a car leaving just after the explosion but where is the footage prior to the explosion showing someone setting up the explosives.

Video link: https://youtu.be/58jc6OZE6Ik

GIB car video link: https://youtu.be/whRv1b7lSak

I think it's something involving electricity due to the blue aura when the explosion happened. This video breaks the footage down and he says it's lightning. Plausible but I think definitely something with electricity is a factor.

Video link: https://youtu.be/58jc6OZE6Ik