I just got home from helping my brother work on a 2002 sportage

and am stumped. my bro had the same problem. when we try cranking the starter the starter spins like there is no restriction and i could see the pulleys and fan turn. but it was like the crank shaft was disconnected based on how fast the starter would turn. but like there where no pistons to hold the starter back.
what i want to know is based on the replies is, could it be the timing belt? and if so, i thought that if the timing belt rips that that would cause the piston to come up and hit the valves and completely kill the motor. isn't the crank shaft connected directly to the fly wheel, and the cams and valves connected to the timing belt? (basing this on a 2005 maximum i killed by dropping a bolt on the timing belt area when i tried changing the water pump.

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only looking for some answers because my brother is very worried about how much this is going to cost him, and i feel bad that i can't really answer his questions. he is 550 mile away from hitting the 100k mark.