The investigation into why a Metrorail Orange Line rain rolled down the tracks with a door open last May is complete and has led to daily safety inspections of a potentially problematic mechanism in Metro’s fleet of 2000 series and 3000 series rail cars.

The incident that occurred outside the Dunn Loring station involved a 3000 series car, but the mechanical part where the issue was identified is similar to what’s in place in 2000 series cars.

The information was presented to the Washington Metrorail Safety Commission on Tuesday.

An in-depth inspection of the part — and application of a mechanical fix to prevent the potential problem that was identified — is expected to be in place on all 2000 and 3000 series cars by the end of the year.

“Until the entire fleet undergoes this engineering overhaul, the daily inspections to test the master controller and the door operation’s integrity will continue daily,” WMSC COO Sharmila Samarasingh reported to the commissioners.

The commission on Tuesday also approved the WMATA investigation into the death of a customer whose electric wheelchair tumbled down an ascending escalator at the Columbia Heights Metro station on Oct 18, 2018.

The investigation report states that the customer pushed a button to call an elevator, waited approximately 15 seconds, departed to the escalator and almost reached the top when his chair flipped over backward and fell to the bottom while the moving stairs continued to operate.

The report concludes that all the equipment involved in the incident was functioning properly as determined by a licensed inspector.