Four fire engines and around 25 firefighters tackled a house fire on Central Park Road in East Ham.
The loft conversion of an end-of-terrace house was destroyed by fire. A rabbit sadly died. There were no reports of any other injuries.
The fire is believed to have been caused by a rabbit chewing through an extension lead.
A London Fire Brigade spokesperson said: “It's important to keep extension leads and other electrical equipment away from pets that may chew cables.
"This incident is also a reminder to test your smoke alarms. There were smoke alarms fitted inside the property, but they didn’t operate.
“Smoke alarms give the earliest possible warning when a fire starts. We encourage everyone to have smoke alarms fitted in every room where a fire could start, plus a heat alarm in the kitchen. It's important to test them regularly.”
The Brigade was called at 2039 and the fire was under control by 2110. Fire crews from Plaistow, Stratford, Leytonstone and Leyton fire stations attended the scene.