i have no clue

ok iv got an 87 civic si ran great no smoke, dident burn oil, car over all ran good, well last night i was letting a buddy of mine drive it and he was at about 5000 rpm in second gear and went to first insted of third some kind of way well directly he pressed the clutch back in and the car died and now when you turn the key the stater just winds and wont turn the motor it wont jump off neither i have no clue what it is the timing belt is still on i pulled the valve cover the rocker arms arent loose and i pulled the plugs none were crushed im at a loss plz hheeeeelllppppp!!!!

Is there an inspection cover for the flywheel ? If there is try turning the crank pulley and see if the flywheel moves.

Have you tried a compression test on the cyclinders ?

Just a couple of thoughts.