SMRT Corp., which operates Singapore’s two oldest rail lines, said it fired eight employees and disciplined three others for their roles which led to a flooding incident last month.

The employees who were dismissed included staff who had falsified pump maintenance records and executives tasked to oversee the work, the rail operator said in a statement on its website on Monday. SMRT’s probe also found a vice president and a senior manager had failed to exercise sufficient supervision and the company reserves its right to pursue legal action against them, according to the statement.

Three management executives were disciplined for “failing to exercise the due care and diligence expected of them,” SMRT said, adding that it has since boosted its maintenance processes and supervisory checks.

Singapore’s rail system has been plagued in recent weeks by disruptions, including a lightning strike following a software glitch that caused a train collision that left more than 30 injured. Last month’s tunnel flooding led to a suspension of some services for 20 hours. The transport woes have prompted an apology from the city-state’s transport minister, while Prime Minister Lee Hsien Loong said the incidents have hurt public confidence.