Three men accused of setting off a deadly gas explosion while stealing copper piping worth about $23 have been jailed pending trial.
The blast killed six people, four of them American tourists, in the heart of Athens' most visited neighborhood.
The case has shocked Greece, where tourism drives the economy and Plaka, the old quarter below the Acropolis, is among the most visited areas. It has also raised questions beyond the three suspects.
Victims' families are pressing authorities to explain how a small theft in an old building could lead to a fatal explosion, and whether gas safety checks and oversight failed.
Investigators say the men broke into a three-story neoclassical building on Lysikratous Street before dawn on Sept. 25 and pulled out a section of copper pipe.
The damage caused a gas leak.
Hours later, an explosion brought down the building.
The suspects admitted being inside but denied causing the blast, according to reports.
One of them, a 56-year-old known as "Boubou," told reporters he was "devastated" and not to blame. Another apologized.
The three face charges including causing an explosion that resulted in death. Police said they have a combined 68 previous arrests for theft, robbery and drug offenses.
The Americans were siblings Florida and Florin Hoxha and their partners, Ian Kirkpatrick and Erisa Cani.
They were staying in a short-term rental and were due to fly home that afternoon. Two other residents also died.
In a joint statement, the families mourned the four, "as well as unborn little Bora."
They called the court's decision an important step, but said the investigation must also examine the building's gas installation, maintenance and safety oversight.
"We want to know not only how the leak was caused, but why the tragedy was not prevented," the families said.