Assertion: firefighter | /r/HasProperty | forced to open holes
Facets:
value: during ventilation
type: TEMPORAL
value: in floors
type: LOCATION
Source sentences:
text: For example, during ventilation, firefighters are forced to either open holes in the roof or floors of a structure (called vertical ventilation), or open windows and walls (called horizontal ventilation) to remove smoke and heated gases from the interior of the structure.