At least four people, including three children, have been killed in a mass shooting at a children's birthday party in California, authorities say.

Three children ages 8, 9 and 14 and a 21-year-old were killed Saturday when gunfire broke out at a banquet hall in Stockton where at least 100 people were gathered, San Joaquin County Sheriff Patrick ...

Detectives believe the gunfire continued outside and there may have been multiple shooters.