After gas alarm:

Dead woman lay in burning apartment in Simmering

Night-time drama in Simmering's Strindberggasse: According to information from "Krone", residents first reported the smell of gas in a residential building. After all the apartments were checked, a fire was extinguished and a lifeless person was found. 

Smell of gas in a residential building - this report reached the Vienna Fire Department at around 1:15 a.m. on Wednesday night. A resident in Strindberggasse witnessed the spectacular scenes and how seven fire engines with 30 men and other emergency vehicles were subsequently deployed. According to fire department spokesman Christian Feiler, a total of 19 apartments were checked and measurements revealed an increased carbon monoxide level. 

Did a cigarette cause a fire in the room? 
When the apartments were checked, it became clear where the smell was coming from. A smouldering fire had spread in a bedroom. It was extinguished with a bucket sprayer while wearing breathing protection, but it was too late to help the occupant. The old woman may have fallen asleep with a cigarette. The police are investigating. The operation, in which no other people were injured, was ended at 2.40 am.