Harper's Island (can be watched on Netflix... www.netflix.com )
Harper's Island is a thriller/mystery show that came out in 2009 and aired on CBS. In each episode at least one character is killed and the cast was not told about their characters' death until the day they were given that script.
"Harper's Island was once the scene of a gruesome series of murders. Now, seven years later, family and friends gather on the island for a wedding, but one by one they begin to die." -IMDb
Trailer:
https://www.youtube.com/watch?v=C75mrJqVKjs