Hammer help

[TCB]

Okay, so I'm working on a zombie mod, but have gotten stuck in the mapping process.
I have a map which is set around a small beach Café that is lifted by pillars to be above the actual water. Beside the café is a large mining tower, with TNT placed around it. There's a large trail of gunpowder to the TNT, that is lit. It acts as a fuse. The players have 15 to kill all the zombies and escape on a boat before the fire reaches the TNT, detonating it, and causing the tower to collapse onto the café.
I am not sure on how to do this. I pretty much need:
• A 15-minute-long fuse leading to explosives
• A way to make the tower break and land on the café
• A boat that will arrive when every zombie is killed.

Any help is greatly appreciated, and sorry if this is a stupid question.

 

[Barnz]

http://developer.valvesoftware.com/wiki/Inputs_and_Outputs

Make a func_button, and env_explosion (give it a name) - go to func_button's propertiers, and set your env_explosion to blow up in 15 minutes (which is equal to 900 seconds) - now, for the escape, make a trigger_once, and make it "kill" (remove) your env_explosion when touched.

 

[Vegeta897]

Oh god it's TGB's lost brother, TheCyanBunny!

 

[TCB]

Haha, thanks for the help, Barnz!