Pressed by senators on what caused the circuit breaker to fail, transportation officials were only able to say that they are still waiting for the forensic findings of the Cybercrime Investigation and Coordination Center, an attached agency of the Department of Information and Communications Technology.

"You can’t say the reason why this happened and we still can’t determine how this really happened. How would we act on this if we don’t know the root cause?" Senate public services panel chair Grace Poe said in Filipino.

CAAP Director General Manuel Antonio Tamayo again led officials in explaining what caused the outage, with him reiterating the same explanation he gave to the transportation panel of the House of Representatives during a briefing last Tuesday.

At the House briefing, Tamayo said the CICC said it is unlikely that the outage was due to a cyberattack, an assertion that the cybercrime center refuted.

Tamayo also admitted that there are no CCTVs monitoring air traffic equipment, which Senate President Juan Miguel Zubiri questioned.