A firefighter has been released from hospital following a four-alarm highrise fire in Thorncliffe Park early Wednesday.

The fire broke out in a sixth-floor unit at an apartment building on Thorncliffe Park Drive near Overlea Boulevard at around 3:30 a.m.

About an hour later, Toronto Fire said the fire had been knocked down.

One firefighter was transported to hospital following a Mayday call, Toronto Fire said.

In a tweet, Toronto Fire Chief Matthew Pegg said the injured firefighter was alert and conscious in hospital as he remained under observation. In a tweet later Wednesday morning, Pegg said the firefighter had been released from hospital without any serious injuries.

No civilian injuries were reported.

It’s not yet clear how the fire started.