Four fraternity members at San Diego State University are facing felony charges in connection with a skit performed at party in which a pledge was set on fire. The San Diego County District Attorney's office said the four all pleaded not guilty on Monday. Caden Cooper, 22; Lucas Cowling, 20; Christopher Serrano, 20; and Lars Larsen, 19, were all charged with at least one felony. Prosecutors say Cowling, Serrano, and Larsen pre-planned the skit during which Serrano would set Larsen on fire. Larsen spent weeks in the hospital for treatment of third-degree burns, mostly to his legs. At least a half a dozen SDSU fraternities have been put on probation over the past two years for violating university policies.