Some of the students tried to jump to safety as the floor gave way. mostly to no avail.
In the video footage posted on social media, people were shouting and dancing before the floor caved in.
"They weren't hurt at all but other people were crying, bleeding, it was just a shocking moment for everyone".
News reports cited a Clemson City Police Department as saying that a call was received about 12:30 a.m. Sunday about the collapse of a floor at an apartment clubhouse.
Witnesses said the party at the event space of an apartment complex was just getting started when the floor collapsed.
A private party was being held at the time of the collapse. "Everyone was on the floor and people were screaming and there was wood sticking up from the floorboards".
'It was a lot to take in'.
Police have said no one was trapped in the collapse, but it's not yet clear if anyone has life-threatening injuries.
The 30 people were transported to area hospitals after officials said Clemson University Fire set up a triage at the scene.
Clemson University President Jim Clements said on Twitter that he is monitoring the situation, and the school tweeted that student affairs representatives were sent to the hospitals where the injured were taken.