A fire at a gas substation in Milton Keynes which forced the evacuation of five families is being treated by police as suspected arson.
More than 30 firefighters were called to Glyn Square, Wolverton, at about 2000 BST on Monday.
Residents were advised to stay inside and keep doors and windows shut. Families from Greenleys were evacuated as a precaution.
Thames Valley Police would like to hear from anyone with information.