Lost Time???

Not PC . Pocket Edition -MCPE 0.10.0 Alpha , Iphone 5c IOS 7.1.2

ok not exactly sure what happened?, but i was currently building a tunnel and once the tunnel was finished i went outside i used the furnace i took my iron ore and iron ingots out, then click X to close furnace interface, then game then closed? i re-opened the game loaded my world and the tunnel was gone it was like i never even started digging as i still had the tools and even stranger i even had the resources still i got from the tunnel?, its like i kept everything in my inv but everything i did in the past hour was like it never happened _