At least 11 people, many of them children, have died in the collapse in the Bavarian town of Bad Reichenhall near the German-Austrian border.
Rescuers worked well into the night to find four others believed to be trapped beneath the collapsed roof.
Braving cold conditions and heavy snowfall, as many as 300 rescue workers used backhoes and their bare hands to sift through the ruin.
But work has been stopped temporarily for fears of the remaining structure collapsing further.
A nation grieves
German Chancellor Angela Merkel expressed her condolences to grieving families and pledged the full support of the federal government to help Bavarian state authorities cope with the disaster.
"I, and all of us, have been particularly moved by the cruel fate suffered above all by children and adolescents who wanted to spend a carefree holiday with their family members," she said.
"We are mourning with the loved ones and our thoughts are with those who lost friends," Chancellor Merkel said.
Hundreds of people gathered in front of the town hall for a candlelight vigil for the dead.
Cause not known
It’s not immediately clear what caused the roof of the 30-year-old building to collapse, in a region accustomed to heavy snowfall.
The coach of a local ice hockey club, Thomas Rumpeltes, said overlying snow was due to have been cleared from the roof prior to the cave in.
Mr Rumpeltes said he cancelled a practice at the rink for a youth team because authorities had told him the roof was going to be cleared.
He said he was told the snow removal was a precautionary measure and that no one had warned him of any risk of that the roof was unstable.
Mayor Wolfgang Heitmeier has rejected calls that it was negligent that the rink was allowed to remain open.
Mr Heitmeier argued the roof had been examined in the late morning of the day of the accident and was deemed safe to withstand the weight of the snow on it.
State prosecutor Helmut Vordermayer said evidence was being collected and an investigation into the accident had been opened.
Two trapped in Czech store
In a similar accident, at least two people are trapped after another roof collapsed in the Czech city of Ostrava, 400 kilometres east of Prague.
According to the CTK news agency, it’s not clear how many people are still inside the supermarket.
It’s believed there, the roof did give way under the weight of heavy snowfall.