The main structure of the small building is a brick and mortar construction. To increase insulation, the walls are quite thick, but the floors are not concrete; instead, they are built using 60 cm wide cement panels laid across the load-bearing beams.
Mountain Eagle used many hand grenades during the assault, and the explosions in the enclosed space caused the ceiling to collapse, revealing the cement panels beneath it.
So when Mountain Eagle's attack was obstructed, his immediate thought was not how to rush in, but rather how to bring down the people on the second floor.
The explosives that Mountain Eagle carried might not be able to destroy the entire small building, but he could collapse one side of the floor, making the most critical area of the second floor cave in.
