"She was well known and popular because she was on staff for a long period of time. I went into the newsroom today to send flowers to her daughters - just a little posy up to the hospital - [and] her colleagues in the graphics department were just visibly shocked.
"This has come as a huge shock to the 3 newsroom in particular."
Slater said Ms Todd's death had left staff "heartbroken" for her daughters and partner.
"We just really want to do what we can to support them. It's a great loss."
Police expect to lay charges against the driver of the other car, which appeared to have crossed the centre line into the path of Ms Todd's car.
"It appears that at this stage, indications are that this is a preventable crash," Sergeant John Roberts said.
An Auckland City Hospital spokeswoman said there had been no change in the conditions of Ms Todd's two daughters.
The 5-year-old was critical but stable and her 7-year-old sister was stable.
TV3 current affairs reporter Paula Penfold posted this message on Twitter: "As we mourn the death of a colleague, we send all our aroha and wishes for her children's recovery."
Radio presenter Alison Leonard posted "RIP Rebecca Todd", while another TV3 staffer said "a great lady" had been lost to the road toll, which last night stood at 299 for the year.
National road policing manager Superintendent Carey Griffiths urged motorists to take care ahead of the Christmas holiday period, which officially begins at 4pm today.
Last year, there were 15 fatal crashes and 19 deaths and Mr Griffiths said he would "love to see that number at zero, or significantly reduced".
