Two quick-thinking school girls averted potential tragedy after a spotting a house on fire in West Hampstead.

Juliet O’Halloran and Emily Jarman, both 16-year-old pupils at South Hampstead High School, were working in one of the school’s IT classrooms last Wednesday when they noticed flames and smoke bellowing out of a house in Crediton Hill.

The pair said they were terrified somebody may be trapped inside.

“We looked out of the window and it was immediately clear that a house was on fire,” they said.

“Obviously, we didn’t know what number the house was but we knew we had to do something!

“We were worried that someone might be in there and unable to get out, so we immediately ran downstairs to alert our deputy head who then made sure the fire service was called.”

After their call, four fire engines rushed to the scene and firefighters battled the blaze for over an hour.

Emergency services were able to reach the house before anybody was hurt.

Investigators believe the fire started by accident.