In 1946, a dangerous radioactive apparatus in the Manhattan Project killed a scientist when his screwdriver slipped. To tell his story, Ben Platts-Mills pieced together what happened inside the room.

Less than a year after the Trinity atomic bomb test, a careless slip with a screwdriver cost Louis Slotin his life.

In 1946, Slotin, a nuclear physicist, was poised to leave his job at Los Alamos National Laboratories (formerly the Manhattan Project). When his successor came to visit his lab, he decided to demonstrate a potentially dangerous apparatus, called the "critical assembly". During the demo, he used his screwdriver to support a beryllium hemisphere over a plutonium core. It slipped, and the hemisphere dropped over the core, triggering a burst of radiation. He died nine days later.

Last week, BBC Future explored the consequences of this fatal accident in a specially illustrated story created by the artist and writer Ben Platts-Mills:

• The Blue Flash: How a careless slip led to a fatal accident in the Manhattan Project

In this gallery, Platts-Mills explains how he composed the illustrations, based on reconstructions created shortly after the accident, archive photographs, and his own mock-up of the apparatus built from household materials.