Three young died last weekend for unknown reasons after attending the "rave" (MACROEVENTS dedicated to electronic music) Hard Summer held in the Californian city of Fontana (USA).The Sheriff's Office San Bernardino County, near the city of Los Angeles, said the three deaths "are being investigated individually" and that, initially, would not be related to each other.It also reported the identity of the deceased, who were between 21 and 22 years.According to local newspaper Los Angeles Times, about 147,000 people attended this year's music festival electronic Hard Summer, held between Saturday and Sunday and included in the poster edges as Major Lazer, Ice Cube or AlunaGeorge.The authorities organized a device with 370 agents Sheriff, supported by 240 security personnel, who made 325 arrests during the weekend.A spokeswoman for the Hard Summer, Alexandra Greenberg, showed in a statement the "sadness" of the festival for the deaths and showed his "condolences" to family and friends, but recalled that "the causes of death have not yet been determined."In the last 10 years, at least 24 people have died from overdoses in "raves" held in the region that make up the southern and central California area as well as Las Vegas.