Complex sentence: Petkovic was an employee at the chain restaurant at the time and and his job was terminated for the impromptu gig that caused families to walk out, bills unpaid and food left uneaten on the tables.
Split into simpler sentences: Petkovic was an employee at the chain restaurant at the time. His position was terminated for the impromptu gig that caused families to walk out, bills unpaid and food left uneaten on the tables.