What we knowAround 11 a.m. on Wednesday, two assailants opened fire in San Bernardino at a party in the Inland Regional Center, police said.
Fourteen people were killed and 17 wounded. The motive is unknown.
Police said there was "some degree of planning." The shooters were heavily armed and had tactical attire.
After an afternoon car chase, two armed suspects were killed by police: Syed Farook and Tashfeen Malik.
A third person was detained but might not be connected to the shooting.
Authorities are searching a home in nearby Redlands.
Anyone who suspects a relative was killed or injured can call a family assistance hotline at (800) 637-6653.