1986 firebird clutch problem.?

i was driving my 1986 trans am today doing around 35km/h when i went to shift from second to third gear. as i pressed the clutch pedal down there was a loud "snapping" noise and it felt as if the pedal was just hanging there. i shifted without the clutch and limped into a parking lot and couldnt get it into gear at all after that. the engine will still start but will not go into gear. before this happened there have been no problems and the clutch seemed healthy. it has a 305 and a 5-speed t-5 trans. any suggestions?