The devastated sister of a man now fighting for life after his western Sydney home was set alight has no idea why someone tried to harm him.
The home on Orth St, Kingswood was well alight about 6.55am on Tuesday, as emergency services raced to the scene.
Helpless neighbours, who could only watch as the home erupted into flames, told firefighters an elderly man was inside.
Know the news with the 7NEWS app: Download today
Fire crews forced their way inside to rescue 71-year-old Terry Moorfield, who was found in a back room barely conscious and unable to walk.
“I knew there was an old man there but I didn’t see him outside, so I told the fire brigade there was someone in there,” neighbour Nigel Kelly told 7NEWS.
Fire and Rescue NSW crews extinguished the blaze.
Moorfield was treated by paramedics and taken to Nepean Hospital in a critical condition.
Steve Perkins from FRNSW said the first responding crews did not report hearing any smoke alarms.
“There was a scooter that was being charged in the front yard and we are investigating if this was a lithium-ion battery fire,” Perkins initially said.
However, after reviewing dash-cam video, police said the fire was now being treated as “suspicious” — and an arrest was made later on Tuesday.
The damage to the home was “quite significant”, Perkins said.
“Although it was external, it crept in under the roof and caused quite a significant amount of damage to about 50 per cent of the premises,” he said.
Moorfield’s sister told 7NEWS he lived at the home for about 40 years and his health began to deteriorate a year ago when his wife died.
She said she has no idea why anyone would want to hurt him and his family hopes he will survive.
Anyone who may have been in the area at the time or has further dashcam footage is urged to contact Crime Stoppers on 1800 333 000.
– With Annie Pullar