Fire crews are still tackling a large blaze at a recycling centre in Potters Crouch.
Four engines, including two from Welwyn and one from Watford, have been at the site overnight and remain there this morning. The blaze has been burning in Appspond Lane since 1am on Sunday morning.
Staff from the National Grid are also at the scene making sure that the overhead power lines in the area are safe.
The A414 and the A4147 remain closed and it is not known when they will reopen.
Hertfordshire County Council has said that steady progress is being made.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here