Classes were canceled Tuesday at the University of California, Santa Barbara, as the college community reeled from the deadly rampage that took the lives of six of its students.

UC Santa Barbara declared a day of mourning and reflection and will hold a memorial service on campus.

UC President Janet Napolitano (neh-pahl-ih-TAN'-oh) ordered flags at all 10 UC campuses lowered to half-staff to honor the victims' memories.

"This is a time for mourning and grieving, and for consoling and supporting each other. It will take time for our UCSB colleagues to recover and heal from this," Napolitano said in a letter to the UC community Monday.

Authorities said a 22-year-old man carried out his attacks Friday night in the Isla Vista community after posting an Internet video that he would slaughter as many people as he could. The attacker died of an apparent self-inflicted gunshot wound to the head after a shootout with deputies.