Many people have been taking news of Joan Rivers’ death on Thursday very hard, but it looks like some are going a step further and actually want revenge. Reports have surfaced that the endoscopy clinic at which the comedy legend was receiving surgery when she stopped breathing is receiving death threats from angry fans, and has had to heighten security. Making matters worse for the clinic are reports that there may have been medical malpractice involved. An autopsy has been performed to determine Rivers’ cause of death, but so far results are inconclusive.

TMZ reports that the clinic has been receiving threats since news broke that Rivers had been rushed to the hospital last week, after she stopped breathing during a routine elective procedure. Messages have included statements like, “If Joan dies so will you,” and “I hope you people die, you killed an icon.” Sources say the clinic has had to close down early some days out of fear for employees’ safety. A rep for the clinic told TMZ, though, that additional security has been hired “only to ensure patient safety and privacy.” Meanwhile, the New York Health Department announced Thursday that they were reviewing the clinic to determine whether or not to launch a full-scale investigation.

It was reported earlier this week that Rivers’ family is considering a lawsuit against the clinic. Sources told the New York Daily News that there may have been wrong-doing ivolved, stating that, “An 81-year-old should not have that procedure as an outpatient, very ill advised.” There is no word yet on whether a decision has been made regarding whether to go forward with legal action, but the Health Department’s findings could largely influence how the family chooses to proceed.

An autopsy has been completed on the comedian, but TMZ reports that the results were inconclusive. The Medical Examiner’s Office says that they will need to further investigate the matter to determine the “cause and manner of death.” The further  investigation will reportedly include running toxicology tests, and interviewing medical professionals who were present during Rivers’ procedure.