Sentence:  With the first reports , Russell 's horse wheeled to the right and ran towards the <WSD>buildings</WSD> while Cook , followed by a hail of bullets , raced towards the arroyo of Salyer 's Canyon immediately in front of him , just reaching it as his horse fell . 
Meaning of the word marked with <WSD> tags:  a structure that has a roof and walls and stands more or less permanently in one place