Rescue crews were briefly evacuated from the site on Friday night, after signs that a neighouring building might be in danger of collapse. The warning turned out to be a false alarm and the search resumed with rescuers removing debris with their bare hands and with heavy lifting equipment.

The two men lived in rented apartments in an adjacent building and were likely buried when the falling archive tore off parts of their house. Six search dogs and two rescue robots developed by a Texan-Japanese team are also sifting through the rubble for survivors. Over 180 rescuers are on the scene, though authorities now believe the men’s chances for survival are slim.

The building, which contained priceless documents about Cologne’s long history, is thought to have collapsed due to construction of a nearby metro line. The Cologne transit authority and the construction firm managing the project reportedly knew of “serious problems” with ground water leakage in the area, which could have eroded the archive’s foundations.

On Friday night, area residents attending an informational meeting about the building collapse demanded a halt to construction along the 4.2 kilometer north-south subway line that was due to open in 2011. The Cologne prosecutor’s office and police are investigating the archive’s collapse.