A college party that went well into the morning did not end well for some students at California Polytechnic State University . Roughly 30 students who had danced and drank the night away were on the roof of a garage when it collapsed underneath them around 6:20am Saturday morning during a St. Fratty 's Day party . Of those , ninw were injured , with eight of the injuries being minor and one serious . In the serious injury , a person 's thigh was impaled by a piece of debris early Saturday , the city said in a statement . Scroll down for video . A roof collapsed early Saturday morning as 30 college students were partying and dancing at a St. Fratty 's Day party . The 1,000 people at the party were mostly students at California Polytechnic State University . Eight others were treated for cuts and bruises . None of the injuries are life-threatening . The off-campus party , which was not affiliated in any way with the college , drew about 1,000 students , and hundreds could still be seen partying in a video that showed the exact moment the roof collapsed . 'We are working closely with fire and hospital officials to stay apprised of the conditions of those who were hurt , ' Cal Poly spokesperson Matt Lazier said in a statement to Mustang News . 'Our thoughts are with those injured , and we wish them a speedy recovery . Cal Poly is also in close contact with local public safety agencies as they work to determine exactly what occurred . Their findings will help inform our own efforts to ascertain what led to this incident and decide how we will respond . ' Nine people were injured , with eight of the injuries being minor and one serious . The university is working with authorities to learn if any college-affiliated organizations were involved in hosting the event . Police Capt . Chris Staley says three people were arrested for misdemeanors as his department and the San Luis Obispo Fire Department brought the scene under control a few hours after the collapse . Staley said the event , and its coming 10 days before St. Patrick 's Day , caught police by surprise . 'This is completely unprecedented , ' Staley told the San Luis Obispo Tribune . 'We 've never had anything like this . ' Lazier meanwhile said the university is working with authorities to learn if any college-affiliated organizations were involved in hosting the event .
A roof collapsed early Saturday morning as 30 college students were singing and dancing at a St. Student 's Day party . The 1,000 attendees at the party were mostly students at # ##ide State University . Nine people were injured , with seven of them minor and one serious . A person 's thigh was crushed by a piece of debris .