A small fire at Delta Air Lines Inc.’s computer center was partly to blame for the network failure that caused massive cancellations worldwide Monday, a spokesman for the Atlanta-based carrier said.

The fire was extinguished without assistance from the local fire department, the spokesman said Thursday, declining further comment.

A power-control module at the company’s Atlanta command center failed and caught fire, leading to the electric surge and a loss of power to the company’s computers, Chief Executive Officer Ed Bastian told the Atlanta Journal-Constitution. Also, about 300 of Delta’s 7,000 servers weren’t wired to backup power, a vulnerability that the company hadn’t been aware of, Bastian told the newspaper.

Delta canceled more than 2,100 flights through Wednesday after the computer-network failure, which started around 2:30 a.m. Monday. The company’s computers were down until about 8:30 a.m.

The airline reported 25 cancellations as of 9 a.m. Thursday, some of which were weather-related.