'collapsed part' is not correct and does not make sense in written English.
If you are referring to the parts of a sentence collapsing into each other, you could use the term 'run-on sentence'. For example: "The phrase was too long, so it turned into a run-on sentence, without proper punctuation."
Israeli rockets collapsed part of the ceiling of the 400-year-old Turkish baths.
The blast blew out all the windows in the school and collapsed part of the building and two neighboring houses.
After isolating the fort by a double ditch, the French undermined and collapsed part of the châtelet and penetrated the main fortress through the latrines.
Last July, in the midst of the renovations, the house was severely disfigured when a fire in the middle of the night collapsed part of the roof, destroying a set of important frescoes.
The collapsed part of the south wall also formerly contained an early 13th-century style double-lancet window.
The earthquake collapsed part of the mosque's façade and caused severe structural damage to the interior columns; as a result, the community feared that the mosque would collapse.
As many as 170 firefighters battled the blaze, which collapsed parts of the roof.
Chest physical therapy makes use of techniques such as breathing exercises, stimulation of coughing, suctioning, percussion, movement, vibration, and drainage to rid the lungs of secretions, increase oxygenation, and expand collapsed parts of the lungs.
The neighbour's house had crashed into their home, collapsing part of a balcony.
A gasoline tanker exploded Wednesday night beneath a highway overpass In Hazel Park, Mich ,near Detroit, collapsing part of the overpass onto the northbound lanes of Interstate 75 below.
These new photos, if verified, don't preclude this, but the fire appears to be coming from inside the building - later engulfing the roof of the parking lot and the cars above - evenutally collapsing part of the structure.
