The Olney home that collapsed on Christmas Eve, injuring two people and putting nearly a dozen at risk, had been flagged twice since August as unsafe, according to officials.

The city was preparing to take the owner of the home to court for not making repairs, Department of Licenses and Inspections officials said Friday.

The 9:30 p.m. collapse affected both sides of a twin home at 125 and 127 W. Roosevelt Blvd. Both are rental properties, officials said.

The damage was most severe at 125, where officials said the front wall collapsed and both a side and back wall bulged and fractured. Five people were home at the time of the failure.

According to Philadelphia property records, that residence is owned by the Philadelphia Land & Building Co. on Salmon Street. Attempts to reach the company were unsuccessful.

The company received a violation notice for the property in August, according to a statement from L&I Commissioner Carlton Williams. Inspectors conducted a follow-up visit the following month, but the homeowner failed to respond and the city was preparing to take the case to court to force repairs, Williams said.

The property is now listed as imminently dangerous and will need to be demolished. If the owner does not do so within 10 days, the city will do so and bill the owner for the cost, officials said.

At 127, a front and a side bearing wall both bulged during the collapse. That home, where six people lived, has since been classified as unsafe, meaning the conditions will need to be addressed soon.

Property records list the owners of that residence as Chang Ta and Ching Wa Liu of Bensalem. Attempts to reach them were unsuccessful.

Williams said the cause of the collapse is still under investigation, but in general the city sees increases in collapses when temperatures drop below freezing and then rise quickly.

The two people injured were taken to local hospitals and are in stable condition, officials said.

tnadolny@phillynews.com

215-854-2730 @TriciaNadolny