Joely Richardson as Dr. Iris Varnack

Justina Machado as Alma Ansen

Ann Cusack as Denise Connelly

Scott Cohen as Governor Mike Newsome

David Ramsey as Curtis Ansen

Peter O'Brien as Alan

Carolyn Dando as Lauren Connelly

Kate Butler as Chief of Staff Jean Loos

Rebecca Hamilton as Sarah Newsome

Kayte Ferguson as Tamara Jones

Kodi Smit-McPhee as Toby Connelly

Stacy Keach as Collin Reed

John Atkinson as Ed Connelly

Trevor Sai Louie as Dr. Kwan

Latham Gaines as Kostmart Manager

Jonny Pasvolsky as Governor Newsome's Aide

Steve Bastoni as FEMA Director McGarrett

Cameron Smith as War Room Staffer

Mia Pistorius as Harried Mother

Eliana Saenz as Armory Nurse

Geraline Knox as Sandra Ling

Judi Farr as Mrs. Koppel

Shireen Shah as Shop Owner

Susan Brady as Female Governor

Lynette Romero as National News Correspondent

Margaret Blay as Alma's Elderly Neighbor

Jerome Ehlers as Chad Sinclair

Mark Tronson as Derek Newsome

Robin Kora as Dying Woman's Husband

Brad Hills as Bart Jenkins

Duncan Young as Suicide Man

Nicki Paull as HHS Sec's Aide

Mark Clare as Transportation Secretary

Alan Lovell as Male Governor

Paul Gittins as Government Worker

Nigel Godfrey as British Correspondent

Costa Ronin as Russian Correspondent

Ferdinand Hoang as Chinese Executive #1

Sandy Winton as Little League Father

Shane C. Rodrigo as Desperate / Reasonable Man

Joseph Woo as Chinese Executive #2

Frankie Fu as Chinese Executive #3

Justin Hansen as Dying Man

Eoin McDonald as Dying Patient

Michelle Mellgren as Kostmart Employee

Linda McFetridge as Harried Mother (uncredited)

Sara Wiseman as Susan Wood (uncredited)

Lynnanne Zager as Dr. Judy (uncredited)

Matthew Chamberlain as Reporter (uncredited)

David Aston as Reporter #1 (uncredited)