What causes a hose to disconnect. And over heat your car

Is this a radiator hose or a heater hose or recovery hose? I have seen strange or simple reasons a hose is found off and caused overheating or loss of coolant my 2008 Silverado bought new went 1000 miles and I noticed a coolant smell so I checked all hoses and found a clamp on lower hose at water pump had never been closed it is the factory quick type that is locked open until released by installer or technician just my luck Chevrolet dealer refilled coolant for free