Brothers Kyle and James Smith from the Vale of Glamorgan were both travelling in the same car which crashed in 2005.
Kyle was 16, not wearing a seatbelt, thrown from the vehicle and died.
James was 15, wearing a seatbelt and survived.
Their mother Angie Smith says she has "no doubt" that she would have lost both boys, had James not been wearing a seatbelt.
More top news
The first planting of the Woodland Trust's WW1 Centenary Wood is set to get underway in the Gwendraeth Valley, near Kidwelly.
This week Hannah is in Carmarthenshire finding out what is happening at the National Botanic Garden of Wales, 15 years after it first opened
A study funded by The Brain Tumour Charity aims to discover how long it takes on average for adult brain tumour patients to be diagnosed.