ATLANTA — New details have emerged about the escalator malfunction at MARTA’s Vine City Station that injured more than 20 people following a Beyoncé concert earlier this month.

A state investigation found that four drive belts were missing from the motors on the escalator that failed, contributing to the incident. The injuries ranged from broken bones to minor bumps and bruises as concertgoers were leaving the packed station.

MARTA has not commented on the findings in the report.

WSB’s Ashley Simmons contributed to this story