As Delta Air Lines claimed the CrowdStrike global IT outage cost the airline $500 million, CrowdStrike is claiming it reached out to help Delta, to which the airline did not answer.

Last week, Delta CEO Ed Bastian said the global outage, which was caused by a failed software update, cost the airline $100 million per day. Now, while Delta is threatening legal action, CrowdStrike is striking back, saying Delta did not take offers to help.