Why does industrial craft crash my minecraft 1.7.2?

So I have got mc forge up-to-date and when I put industrial craft into my mods folder it crashes just after the mojang screen. This is what it says…

at cpw.mods.fml.common.LoadController.trans…
at cpw.mods.fml.common.Loader.loadMods(Load…
at cpw.mods.fml.client.FMLClientHandler.beg…
at net.minecraft.client.Minecraft.func_7138…
at net.minecraft.client.Minecraft.func_9999…
at net.minecraft.client.main.Main.main(Sour…
at sun.reflect.NativeMethodAccessorImpl.inv… Method)
at sun.reflect.NativeMethodAccessorImpl.inv… Source)
at sun.reflect.DelegatingMethodAccessorImpl… Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.minecraft.launchwrapper.Launch.launc…
at net.minecraft.launchwrapper.Launch.main(…
Caused by: java.lang.ClassNotFoundException: ic2.common.IC2
at net.minecraft.launchwrapper.LaunchClassL…
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at cpw.mods.fml.common.ModClassLoader.loadC…
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at cpw.mods.fml.common.FMLModContainer.cons…
at sun.reflect.NativeMethodAccessorImpl.inv… Method)
a

Try using an older/newer build of the mod that is still 1.7.2