Innertube just popped?

[RiflemanSmith]

About 3 am last night I heard a popsheeeeesh got up had a look and my sons front wheel was flat.
Thought it was strange and went back to bed.
I had pumped up the tires the day before, they were not over inflated they were 5 PSI off the max.
The innertube has a large split in the middle, I patched over it today.
Went to pump the tire up got to 20 psi and the patch split directly over the split.
I couldn't feel any foreign bodies in the tube?

 

[RWright]

You may have pinched the tube between the rim and the bead on the tire. I have done it before, it left a long split in the tube. Make sure the tube is inside the tire bead before you pump it up. I had one tire with a weak section in the sidewall that would let the tube slide out of the bead. I blew a few tubes out trying to figure out what was going on. I would replace a tube with a rip in it too. A very small hole I will patch but a rip I won't reuse the tube.

 

[Pat "5mph"]

Got this happening too. As @RWright says, it was probably a pinched tube.
Mine had a rip like the op's, all good since replacement.

 

[RiflemanSmith]

I have never taken the tire off and is never gone so low as to be flat.
The split if it was on the tire would be dead centre of the tread exactly in the middle of the tire.

 

[grumpyoldgit]

Take the tyre & tube off,throw the tube away.Turn the tyre inside out to check it,check the rim,& rim tape.Re fit,simples.

 

[andrew_s]

Also check that the wire/kevlar bead isn't splitting away from the rest of the tyre at some point. This can happen if the brake blocks overhang the rim braking surface, or the tyre has been used too long at lowish pressures. It's probably not this, as I'd have expected a loud bang rather than a popsheeeeesh if it was, but check anyway.

 

[RiflemanSmith]

Take the tyre & tube off,throw the tube away.Turn the tyre inside out to check it,check the rim,& rim tape.Re fit,simples.

I know how to check for foriegn bodies and faults after repairing or fitting a new inner tube.
The bike is my sons and has only been ridden 4 or 5 times since new, it has disc brakes.
I think the inner tube probably had an inherent weakness as it just popped like it was over inflated which it wasn't.