What happened to Catullus’s brother?

Catullus’s poetry records the death of his brother, an event that caused the poet significant emotional distress. While the specific circumstances of his brother's passing are not detailed, Catullus famously visited his brother's grave in the Troad, a region in Asia Minor. This visit inspired one of his most poignant and transcendent compositions, a lament that remains a notable part of his surviving work.12