How do I trigger an event after destroying multiple objects?

Hi, I’m trying to create an Escape puzzle where the player is trapped and a ceiling of spikes is slowly descending, I’m having trouble with one last thing before it’s finished;

The player has to destroy 6 Fragile Spikes with a Laser which will then destroy the ceiling and reveal the escape route, my problem is how do I get the game to recognise whether all the spikes are destroyed or not, so once the last spike is destroyed, the event happens.

you have a few options here. you could have the spikes call a event just prior to them being destroyed, you could bind an event to the destruction of the spike (the bind would be in the level blueprint or in another actor), or you could use a timer to get all spike actors in the level at a regular interval then once you get all the actors check the length of the array it returns if its length is 0 or less then trigger another custom event.

personally i would go with the custom event but thats just because its easy to implement and because its more my style.