Endangering the safety of persons travelling by tramway by unlawful act or willful omission

If any person by unlawful act or by any willful omission or neglect or by tampering with safety devices, endangers or causes to be endangered the safety of any person travelling on or being upon on any tramway or endangers the tramway system, or obstructs or causes to be obstructed or attempts to obstruct any rolling stock upon any tramway system, he shall be punishable with imprisonment for a term which may extend to seven years: Provided that in the absence of special and adequate reasons such imprisonment shall not be less than,- (a) six months in the case of first conviction; and (b) two years in the case of conviction for the second or subsequent offence.