A grizzly bear expert says fatal attacks such as the one on a woman and her baby in Yukon are unusual and it is important to have a thorough investigation into their deaths.

The Yukon Coroner's Service says Valerie Theoret, who was 37, and her 10-month-old baby died Monday.

Chris Servheen, who was the grizzly bear recovery co-ordinator for the U.S. Fish and Wildlife Service for 35 years, says it is sad to see the death of a woman and her child.

But he says that is why it is important to find out why it happened.

Servheen, who has investigated the past eight fatal grizzly bear attacks in the U.S., says it could have been a surprise encounter or a case where a hungry bear was looking for food.

RCMP and Yukon's department of the environment are assisting the coroner's service with its ongoing investigation.