Mama Cass also known Cass Elliot, real name Ellen Naomi Cohen, died in her sleep of a heart attack in her hotel room after a sell out concert at the London Palladium on the 29th July 1974.
She did not choke on a sandwich, she died of heart failure. 4 years later Keith Moon (the who drummer) died in the exact same hotel room (flat number 12, 9 curzon place).