Raquel Aldana taught in Las Vegas for almost a decade.
The now University of California, Davis law professor started Monday morning reading the news on her phone.
"I saw my Facebook postings, I still have many former students and colleagues," said Aldana. "All of whom who were posting about both being safe but also being completely terrified by this tragedy."
Aldana taught law at University of Nevada, Las Vegas from 2000-09. She said her colleagues at UNLV are helping victims, including preparing for blood collections.
Meanwhile, flags flew at half-staff across UC Davis Monday. Counseling was also available to students.