Volvo: 2001 volvo s 60

Question
My son was driving and said car made a hum sound and stalled..Thought it was alternator changed but still will not start. Checked spark plugs and they were fine. Husband disconnected starter and tried hand cranking engine.  It will not move at all.  Could engine be seized?

Answer
It is possible it broke the timing belt and it is a interference engine and would bend valves .It rarely seizes crank or rings unless very low on oil .either way if the engine is seized it will be exspensive, and on a vehicle of that age your best option would be a used engine if the rest of the car is sound .