A family home in Leiferder Lower Saxony has been left inhabitable after a rocket crashed through the roof.
“We're trying to find out how this happened exactly,” Elisabeth Hoffmann spokeswoman from the Technical University of Braunschweig told broadcaster NDR on Tuesday.
Launched on Sunday from an airfield near Hillerse, the rocket's flight did not go as planned.
The missile went off course and crashed through the roof of the residential building, just one kilometre away.
According to Hoffmann, the 1.6-metre-long, 8 kilo rocket designed by university students was only supposed to fly a maximum of 800 metres.
The family – a 38-year-old mother and her two children, aged 6 and 2, were not at home when when the rocket tore through the roof.
It shot through the wall of the children's bedroom and blew a fuse box off the wall. Other rooms in the house were also damaged.
Repairs have started on the home, but it is still unclear how much they will cost and who will pay for them.
The family initially thought it was a military explosion. “I never would have thought that something so dangerous would be allowed to fly,” said homeowner and father Jakob Schweissguth.
Schweissguth said he was "deeply disappointed" that the university was yet to get in touch.
Permission to launch the rocket, which can ascend up to 1,000 metres, was given by a consortium of authorities together with the university.
According to a police spokesman, they are now looking into the case and have asked why the researchers were able to launch the test rocket in a residential area.
It was the rocket's third flight - until the incident everything had always gone to plan, Hoffmann told NDR.
Hoffman said no further rockets will be launched until the exact cause of the error had been identified.