Two two cousins were amongst the six Irish students killed in the incident on Tuesday.
The balcony fell away from the fifth floor of a Berkeley apartment building during a birthday party, throwing 13 people to the street 50 feet below.
Ashley Donohoe, 22, from California, and her cousin Olivia Burke, 21, from Ireland were remembered in a Catholic Mass, according to The Daily Mail.
Over the weekend they were described as kind and fun-loving.
Wreaths of white flowers and green ribbons decorated St. Joseph Catholic Church in Cotati.
Revd Daniel Whelton led the service at the same church where Ashley was baptized: "Growing up, they would dress alike and they would try to fool their parents into thinking they were twins."
Revd Whelton said Donohoe's mother told him the two were embracing when they died: "In life they were together and in death they are together," he said.
The four other victims were mourned at a Friday night vigil in Oakland.
The bodies of four of the Irish victims were repatriated on Sunday.
