In her first public remarks as Joe Biden s presidential running mate, Sen. Kamala Harris (Calif.) dedicated part of her speech to his son Beau Biden , whom she was close friends with up until his 2015 death.

Harris, who joined the prospective Democratic nominees ticket on Tuesday, became close with Bidens eldest son when they were both serving as state attorney general he in Delaware and she in California.

Ever since I received the call, Ive been thinking, yes, about the first Biden that I really came to know, and that of course is Joes beloved son, the California senator said of Beau, who was 46 when he died from brain cancer, while speaking in Wilmington, Delaware.

The two became close in 2011, in the midst of the housing crisis, when every attorney general banded together to investigate the banks.

In the midst of the Great Recession, Beau and I spoke on the phone practically every day. Sometimes multiple times a day, she recalled, working together to win back billions of dollars for homeowners from the big banks of the nation that were foreclosing on peoples homes.

Both found themselves skeptical of the process and ended up collaborating on their own separate probe. The move paid off for their states, and the pair spent several more years partnering on other initiatives.

Let me just tell you about Beau Biden, Harris continued Wednesday. I learned quickly that Beau was the kind of guy who inspired people to be a better version of themselves. He really was the best of us. And when I would ask him, Whered you get that? Whered this come from? Hed always talk about his dad.

Harris is the first Black woman and the first Asian American to be selected as the running mate of a major partys presidential candidate. She and Biden are expected to accept the nomination at the Democratic National Convention next week.