The public are urged to avoid J8 of the M1 after a fire broke out on the roof of a building in Hemel Hempstead.
Hertfordshire Fire and Rescue Service, who were called at 8.09am, confirm the fire broke out in the air conditioning units on top of Breakspear Park on Breakspear Way.
Five fire engines, the aerial ladder unit and police are in attendance.
Social media reports suggest everyone evacuated the building safely.
Some congestion will occur on surrounding roads including J8 of the M1 and drivers are urged to avoid the area if possible.
— Jim Smith (@JimSmith1974) July 3, 2019
More to follow.