The ground crew of Deutsche Lufthansa AG went on strike early Monday over working conditions, causing the cancellation of almost all of the airline’s flights, a trade union official said.The strike started around 4 am (0200 GMT) in Stuttgart and an hour later in other airports around the country. It was announced in advance and was planned to last 24 hours.“The terminal is almost empty, because most passengers were prepared” and made other arrangements, said Gerold Schaub of the trade union Verdi, speaking from Frankfurt airport.Of the planned 1,720 Lufthansa flights Monday, only 32 were expected to run, the company said Saturday.It is the second wave of strikes over wages and working conditions for about 33,000 technicians and service workers. The first action by Verdi resulted in 700 flight cancellations on March 21.Verdi representatives have demanded job guarantees and a 5.2 per cent raise. Lufthansa has countered with a modified offer that would take job classification and performance into account.It would provide raises of more than 3 per cent for certain job groups over 29 months, but Verdi has responded that some categories of worker would end up earning less in real terms.