After the house collapsed in Hemer, Sauerland, as a result of an explosion, a man was rescued from the rubble.
Rescue workers first provided him with medical care on site and then wanted to take him to a clinic, the police said early Saturday morning.
At the same time, according to the information, the rescue of another person was being prepared.
A third person was believed to be under the rubble.
Emergency services could not initially contact her.
According to the latest information, there is already a victim with serious injuries in the hospital.
Another person was rescued with minor injuries.
The man was lying high up on the rubble mountain.
Three of the eight residents of the house were probably not at home at the time of the collapse.
Aerial photos show a debris field where an apartment building previously stood.
The salvage operation is a race against time.
With heavy equipment in the form of excavators and cranes, the rubble has to be carefully cleared away piece by piece in order to get to the buried people.
The house is said to have been a six-party house.
"Unfortunately, it collapsed completely, there is no stone left standing," said fire brigade spokesman Andreas Schulte.
The exact cause of the explosion is initially unclear - but it was a gas explosion, report the fire brigade and police.
The area around the scene of the accident was cordoned off.
The detonation shattered windows on neighboring houses.
A structural engineer must now clarify how much the houses have gotten.
That's how long they stayed evacuated, a police spokeswoman said.
Hemer is a town with 34,000 inhabitants in the Märkisches Kreis in Sauerland.
It is the eastern neighboring town of Iserlohn.