Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Name | Deceased Spouse | Cause of Death | Date of Spouses Death | Length of Marriage | Children Together | Current Marital Status |
| --- | --- | --- | --- | --- | --- | --- |
| Samuel Beckett | Suzanne Déchevaux-Dumesnil | Unknown | July 17, 1989 (aged89) | 28 years | None | Deceased (1989) |
| Jan Berenstain | Stan Berenstain | Unknown | November 26, 2005 (aged82) | 59 years | 2 Sons (Leo, Michael) | Deceased (2012) |
| Ray Bradbury | Marguerite McClure | Not Known | November 24, 2003 (aged81) | 56 years | 4 Daughters (Susan, Ramona, Bettina, Alexandra) | Deceased (2012) |
| Mary Welsh Hemingway | Ernest Hemingway | Suicide | July 2, 1961 (aged61) | 15 years | None (miscarriage) | Deceased (1986) |
| Norris Church Mailer | Norman Mailer | Acute Renal Failure | November 10, 2007 (aged84) | 27 years | 1 Son ( John ) | Deceased (2010) |
| Frederica Sagor Maas | Ernest Maas | Natural Causes | July 21, 1986 (aged94) | 59 years | None | Deceased (2012) |
| Edgar Allan Poe | Virginia Eliza Clemm Poe | Tuberculosis | January 30, 1847 (aged24) | 11 years | None | Deceased (1849) |
| Dr. Seuss | Helen Palmer Geisel | Overdose of Barbiturates | October 23, 1967 (aged68) | 40 years | None | Deceased (1991) |
| Robert Treuhaft | Jessica Mitford | Lung Cancer | July 22, 1996 (aged78) | 53 years | 2 Sons (Nicholas, Benjamin) | Deceased (2001) |
Question:
What was the cause of death in the marriage that lasted 28 years? 
Answer:
Unknown