The Toronto Transit Commission has issued a formal public apology to commuters frustrated by a series of rush-hour delays on Monday.

“I want to say sorry for the poor subway service that we offered last night,” the transport agency’s CEO Andy Byford said in a one-minute video statement released Tuesday afternoon.

Speaking at Bloor Station, Byford explained there were a number of delays that caused regular services to be interrupted during the peak evening commuting hours.

He said two track-level fires at Eglinton and Keele Stations resulted in a service suspension, as it was necessary to wait for the Toronto fire department to investigate and give an all-clear before service could resume.

Byford said the 24 minute delay at Dupont Station after a train’s door opened while it was travelling inside the tunnel is being investigated as well.

The TTC also dealt with a number of passenger service alarms which were activated during the delays.

On Monday, the string of delays prompted the TTC’s spokesperson Brad Ross to tweet that “Subway service levels tonight were unacceptable.”

Ross said the Dupont Station incident “should not have happened.”

Monday evening’s problems came less than a month after the TTC announced its first-ever customer charter aimed at improving rider relations.

Ross said the TTC “failed” in providing reliable service, one of the key core promises in the customer charter.