Kate Winslet as Sarah Pierce

Patrick Wilson as Brad Adamson

Jennifer Connelly as Kathy Adamson

Gregg Edelman as Richard Pierce

Sadie Goldstein as Lucy Pierce

Ty Simpkins as Aaron Adamson

Noah Emmerich as Larry Hedges

Jackie Earle Haley as Ronnie J. McGorvey

Phyllis Somerville as May McGorvey

Helen Carey as Jean

Catherine Wolf as Marjorie

Mary B. McCann as Mary Ann

Trini Alvarado as Theresa

Marsha Dietlein as Cheryl

Jane Adams as Sheila

Raymond J. Barry as Bullhorn Bob

Sarah Buxton as Slutty Kay

Thomas Greaney as Troy

Anna Audia as Isabella

Celestial Hakim as Courtney

Hunter Reid as Christian

Chadwick Brown as Tony Correnti

Phil McGlaston as Dewayne Rogers

Bruce Kirkpatrick as Bart Williams

Adam Mucci as Richie Murphy

Chance Kelly as Pete Olaffson

Rebecca Schull as Laurel

Crystal Field as Josephine

Lola Pashalinski as Bridget

Walker Ryan as "G"

David Cole as Skateboarder 2

Weston Elrod as Skateboarder 3

Erica Fae as Richard's Secretary

Leo Trombetta as Frank

Christopher Nicholas Smith as Steak House Waiter

Adam Sietz as Large Man

Tom Perrotta as Small Man

Stan Carp as Cabbie

Sandra Berrios as Kind Woman in Hospital

Ivar Brogger as ICU Counselor

Myra Turley as ICU Nurse

David Rowden as Tow Yard Attendant

Paul Mott as Boy in Kathy's Documentary

Margaret Pace as EMT

Beatrice Rigaud as Concerned Mom at Pool #1

Mary Goggin as Concerned Mom at Pool #2

Jillian Lindig as Concerned Mom at Pool #3

William Harvey as 1st Policeman at Pool

Casper Andreas as 2nd Policeman at Pool

Matt Garifo as Lifeguard

Brooke Fazio as Snack Girl

Monica Dobson as Wading Pool Mom

Ken Tirado as Bartender

Carlie LaPorta as Child at Steakhouse

Cody Rubenstein as Child at Steakhouse

Joe Guest as Ted from Richard's Office

Bruce Lee Gross as Ray from Next Door

Patrick Larkin as Auditor Team Captain

Michael Diesel as Police Officer at McGorvey's

Jennifer Rainville as Reporter - "Channel 5 News" Segment

Gary Anthony Ramsay as Off-Screen Anchor - "Channel 5 News" Segment (voice)

Patricia A. Gangemi as Concerned Parent #1 - "Channel 5 News" Segment

Cynthia L. Wiese as Concerned Parent #2 - "Channel 5 News" Segment

Loren Wiese as Concerned Parent #3 - "Channel 5 News" Segment

Clare F. Mitchell as Concerned Parent #4 - "Channel 5 News" Segment

Leon Vitali as Oddly Familiar Man

Conrad Angel Corral as Slutty Kay Fan Club Member

Darrell Geer as Slutty Kay Fan Club Member

Gil Ira Hayes as Slutty Kay Fan Club Member

Mark A. Pierce as Slutty Kay Fan Club Member

Marshall Lefcourt as Slutty Kay Fan Club Member

John Begley as Background Football Player

Mike Ganim as Background Football Player

Travis Koestler as Skateboarder

Daniel Falla as Skateboarder

Luis Tolentino as Skateboarder

Tugman Tookmanlian as Skateboarder

Will Lyman as Narrator (voice)

Steve Antonucci as Swimmer (uncredited)

Deanna Dys as Vanity Fair Pool Girl (uncredited)

Ashley Fung as Girl at the Pool (uncredited)

Marianne Hettinger as Sunbathing Model (uncredited)

Callie Thompson as Little Girl at Pool (uncredited)