At least one person was killed and three injured on Friday when part of an oceanfront bluff collapsed on beachgoers in California, authorities said.The fatal incident took place near a staircase leading to Grandview Surf Beach, north of San Diego.At least two people had to be rescued from the debris after being trapped, said Lieutenant Ted Greenawald of the San Diego County Sheriff's Department.There were no immediate details on the person who died, he said.Encinitas lifeguard captain Larry Giles told local reporters that three people were hurt and taken to hospitals, including one who was critically injured and had to be airlifted.Giles said rescuers were working with dogs to search for other possible victims.At least one person was killed Friday when part of a sea bluff in Encinitas, California collapsed onto a group of beachgoers. WE-012FR pic.twitter.com/gy88TuL77l— CNN Newsource (@CNNNewsource) August 3, 2019 The beach where the incident took place is located along sandstone cliffs that have rapidly eroded over the years.In 2000, a landslide in the area killed a woman who was on a beach watching her husband surf.The city of Encinitas has placed warning signs along several locations."Because of frequent bluff failures, a great deal of consideration has been given to ensuring the safety of those who visit our beaches," according to the city's website. "Please be aware that in most areas hiking near or directly on top of the bluffs is prohibited."It is also important for visitors to avoid standing or sitting directly underneath unstable bluffs, since they may collapse."