Retiree William Tay, 66, was moved by photos of the 1961 Bukit Ho Swee fire at a new, free exhibition called We: Defining Stories.

As a young boy living in a kampung on nearby Towner Road, he saw smoke from the fire tearing through the squatter homes of 16,000 residents. "We felt very sad... we could see the smoke but couldn't do much to help," he said during a preview of the exhibtion on Saturday.

Presented by The Straits Times and the National Museum of Singapore (NMS), the free photography show features more than 400 photographs depicting the nation's landmark moments from 1950 to 2013.

The photos from the paper and museum's collections, have been divided into six sections: Merdeka (freedom in Malay), Home, Challenges, Heroes, So Singaporean and Our Stories.

Mr Tay was one of hundreds of ST readers who enjoyed an exclusive preview on Saturday - a day ahead of its official opening, as part of the Straits Times Appreciates Readers programme.

He was also one of 60 treated to guided tours of the exhibition.

Mr Tay said it was nice seeing photos that made the news over the past few decades. "Growing up in a kampung, we didn't have newspapers or a television set. Whatever news we got, we heard from my parents and neighbours.

"Today, I got to see these photos in person and relive those moments," he said.

Straits Times photo editor Stephanie Yeow, encouraged people to attend the show. She said the exhibition has something for everyone.

NMS director Angelita Teo said the aim of the exhibition is to stir the imagination of visitors, encourage dialogue and discussion. "We hope that it will serve as a poignant reminder that as a people, our stories hopes and dreams are intricately and beautifully intertwined."