The Department of Transportation (DoTr) has launched an investigation into an MRT-3 service disruption that halted rush-hour transit Wednesday morning, prompting officials to offer free rides to all commuters for the rest of the day.

Transportation Secretary Giovanni Lopez ordered railway management and maintenance contractor Sumitomo Corp. to explain the cause of the breakdown, which occurred between the Buendia and Guadalupe stations at approximately 5:30 a.m.

Normal operations resumed at 6:57 a.m., nearly an hour and a half after the issue was reported and as an apology for the inconvenience, the rail line began offering free rides to all commuters starting at 12 p.m. Wednesday.

Transportation officials said the cost of the fare subsidy will be charged to Sumitomo.

Lopez directed MRT-3 general manager Michael Capati to submit a detailed report within 24 hours explaining the incident and justifying why administrative sanctions should not be imposed.

“We have to identify the cause of the disruption,” Lopez said. “We will do everything to ensure the continued and reliable service of our trains for our commuters.”

Lopez also instructed MRT-3 management to issue a show-cause order to Sumitomo and its consultants to account for the incident. The Japanese firm is responsible for the rehabilitation and maintenance of the rail system.