The house was heavily damaged. All the fires were set within a radius of 400 metres.
Responding to a burglar alarm in Hakunila at 2:40 am, police discovered that an attempt had been made to set a fire in a local daycare centre. Soon afterwards, a toy storage shed at another nearby daycare centre was found to be ablaze.
The next alarm was at a residence where a five-member family had been awakened by their barking dog to find flames spreading from their terrace to the roof.
The last alarm of the night was at 4:04 am at yet another daycare centre where there had been a break-in. An unsuccessful attempt had been made to set it on fire, as well.
Within a matter of minutes, police took a man into custody who is suspected of setting all four fires.
In Järvenpää overnight, officials recorded the 15th unexplained fire within the past few months.
This blaze destroyed an outbuilding which housed a two-room holiday dwelling, a garage and a carport. No one was injured in the fire.