Regional Jet 900 (CRJ900)
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 1
Communication Breakdown
ATC Issue All Types; Airspace Violation All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification
Environment - Non Weather Related; Chart Or Publication; Human Factors; Procedure
I was on Ground Control and Clearance Delivery; I read clearances as normal and coordinated flow times. The facility both Tower and Radar were evacuated and went to ATC Zero for COVID-19 Cleaning. I instructed all IFR aircraft on frequency to contact ARTCC for IFR services and broadcast it on the ATIS frequency.  I did not specifically tell the IFR aircraft that had already been read clearances while the airport was controlled to hold for release. After the facility had been evacuated and the airport deemed uncontrolled; an IFR aircraft departed without coordinating with ARTCC. I would recommend a procedural amendment to the local contingency plan to broadcast that all IFR aircraft that had been issued IFR clearances to hold for release and contact ARTCC or FSS to coordinate their departures prior to taking off.
Received pre departure clearance from ZZZ clearance. Clearance informed us the Tower would be closing due to the Tower getting cleaned. Departures/Arrivals and Ground and Tower would be closed. They asked if we would be gone before then and we said probably not. They did not give us a hold for release instructions. They gave us Center frequency before the tower closed. We finished; pushed back and broadcast over CTAF we would be taxiing out. We attempted to contact Center several times before departing. We called in the blind on CTAF as we took the runway and departed. We contacted Center at around 1;500 feet and continued on our way. 10 minutes later Center informed me to contact Center via the telephone for a possible pilot deviation. It is unknown what the actual deviation may have been if there was a pilot deviation.
A Tower controller and flight crew reported the flight crew departed an airport with a closed tower without approval for release from the ARTCC. The Tower Controller reported they failed to advise the flight crew to hold for release after issuing their clearance prior to Tower closing.