POLICE have said a fire at a Waverley unit yesterday was deliberately lit and early estimates indicate the damage bill may be as much as $250,000.
The resident of the Allwinton Court property was not home at the time of the fire.
The Tasmania Fire Service was alerted to the fire at 5.14pm which was attended by Launceston and Ravenswood units.
The fire was deemed under control by 6.45pm.
Neighbours described hearing an explosion before seeing flames coming from the windows.
Brodie Rumbel, 17, said he was the only person at the unit complex with access to an outdoor tap.
"There was a fireball that looked like a person, but when I went to look there was no one inside," Mr Rumbel said.
Firefighter Anthony Goss said the building was "fully involved" and it was found that the three adjoining units had sustained some damage from the fire.
Neighbours who had helped with the fire were checked by the Tasmania Ambulance Service for smoke inhalation.
Mr Rumbel said he had been hit by a piece of glass when the unit's windows exploded. No further injuries were reported.
According to police, the unit complex at Allwinton Court is owned by Housing Tasmania.
Three adjoining units all sustained some damage from the fire. Police say early estimates put the damage bill at $250,000 - $150,000 damage to the first unit and in excess of $100,000 to repair damage to the adjoining units.
Police say they are following a specific line of inquiry but so far no arrests have been made.
People with information can call police on 131 444 or report anonymously at Crime Stoppers on 1800 333 000.


