Dozens of firefighters took part in a training exercise in an old Sheffield school to put their skills to the test.
They were faced with a scenario of a huge blaze in a building, with people trapped inside.
The exercise was carried out at the former Prince Edward School on Queen Mary Road, Manor.
Fire chiefs said the aim of the exercise was to test incident command and control procedures, firefighting skills, search and rescue operations, casualty handling and the use of breathing apparatus.
A South Yorkshire Fire and Rescue spokeswoman said: "The exercise formed part of an ongoing aim to continually improve major emergency response procedures.
“Thankfully, large scale incidents such as this are quite rare, but testing our crews with live exercises is vital to ensure they are prepared if something like this does occur.
"On arrival the crews were faced with a difficult rescue scenario. Wearing breathing apparatus the firefighters entered the smoke filled building and recovered all the casualties, bringing the exercise to a successful conclusion.”