Ushu

Ushu (in the Amarna Letters Usu) was an ancient mainland city that supplied the city of Tyre with water, supplies and burial grounds. Its name was based upon the mythical figure Usoos or Ousoüs, a descendant of Genos and Genea whose children allegedly discovered fire, as recorded by Sanchuniathon (Sankunyaton).
1350 BC, Amarna letters "Usu".
The 1350-1335 BC Amarna Letters correspondence refers to mainland Usu in three letters of Abimilku of Tyre. The three letters, EA 148, 149, 150-(EA for 'el Amarna'), are the only references to Usu in the 382 letters corpus and are grouped because of the topic, partially Usu, of the three letters.
Of note, Abimilku is nowhere else referenced by name in any other letters of the correspondence, except his own letters, all addressed to the Ancient Egyptian pharaoh. Abimilku's ten letters, EA 145 to EA 155, mostly have the conflict of Tyre with Zimredda (Sidon mayor), the Habiru, or Aziru of Amurru-(especially EA 148, with Usu). Zimredda is the topic of five of the ten letters. In letter EA 149, with commissioner Haapi, the pharaoh is seeking information about Zimredda.
In the three letters with Usu, water, wood, straw, clay and burial grounds (the dead) are referenced. Pottery may be implied with some of the materials, as well as food, the straw or wood for fires.