Green’s Dictionary of Slang

(US) abandoned, deserted, esp. by one owing money.

1905		H. Green Actors’ Boarding House (1906) 339: There wasn’t a trunk there! She had been bunked!
1908		S.E. White Riverman 52: He got ‘bunked’ [...] ‘How much?’ asked Simms. ‘About fifty dollars,’ replied the boy.