The New York City Council unanimously passed legislation in mid-September that mandates an increase in late-night inspections and substantially increases fines that an employer pays for locking in workers against their will, reports the New York Committee for Occupational Safety and Health.

The bill increases fines tenfold for businesses that lock employees in at night, from $500 to $5,000 for the first offense. Subsequent offenses would raise the penalty to $20,000.

The new law also provides protections for workers who report violations.

Many New York City store owners and managers routinely lock in the midnight shift of janitors and stock clerks, most of whom are immigrants or minorities, allegedly to prevent theft, even though doing so violates the City’s fire code, according to NYCOSH.

"We are very glad that the City Council has passed the bill," said Susan McQuade of NYCOSH, "but this law is not going to enforce itself. Everyone who has supported it needs to educate workers and employers about the hazard and to tell city officials that they have an obligation to protect these vulnerable workers."

Nearly a century ago in New York City 146 garment workers were trapped behind locked doors and died in the Triangle Shirtwaist fire, one the landmark tragedies sparking public awareness of industrial safety hazards in the U.S.