The ExplosionDetonate Event is fired shortly before an explosion starts. It cannot be canceled.

You will need to cast the event in the function header as this class:
crafttweaker.event.ExplosionDetonateEvent
You can, of course, also import the class before and use that name then.

ExplosionDetonate Events implement the following interfaces and are able to call all of their methods/getters/setters as well:

• IExplosionEvent

The following information can be retrieved from the event:

ZenGetter	ZenSetter	Type
ZenGetter affectedEntities	ZenSetter ​	Type IEntity[]
ZenGetter affectedPositions	ZenSetter ​	Type IBlockPos[]

The following information can be retrieved from the event:

ZenGetter	ZenSetter	Type
ZenGetter world	ZenSetter ​	Type IWorld
ZenGetter explosion	ZenSetter ​	Type IExplosion
ZenGetter position	ZenSetter ​	Type IBlockPos
ZenGetter x	ZenSetter ​	Type double
ZenGetter y	ZenSetter ​	Type double
ZenGetter z	ZenSetter ​	Type double