With the attacks unfolding, air traffic officials began issuing warnings through the Aircraft Communication Addressing and Reporting System (ACARS). Ed Ballinger, the United flight dispatcher, began sending text cockpit warnings to United Airlines flights at 09:19, 17 minutes after he became aware of Flight 175's impact. Ballinger was responsible for multiple flights, and he sent the message to Flight93 at 09:23. Ballinger received a routine ACARS message from Flight93 at 09:21: "Good morning...Nice clb (climb) outta EWR [Newark Airport]." The message commented about the sights from the cockpit and the weather, and was signed off with the initial, "J.", indicating it came from Jason Dahl, who knew Ballinger. At 09:22, after learning of the events at the World Trade Center, LeRoy Homer's wife, Melody Homer, had an ACARS message sent to her husband in the cockpit asking if he was all right. At 09:24, Flight93 received Ballinger's ACARS warning, "Beware any cockpit intrusiontwo a/c [aircraft] hit World Trade Center". At 09:26, after the pilots twice checked in with a routine altitude and weather report to an air traffic controller at the FAA's Cleveland Center, Dahl wrote a hasty, misspelled ACARS reply: "Ed cofirm latest mssg plz-Jason". At 09:27:25, as the aircraft was crossing into eastern Ohio airspace, the flight crew responded to a routine radio call from a Cleveland air traffic controller, who told them to watch for another plane twelve miles away and two thousand feet above them. They said contact was negative and they were looking. This was the last communication made by the flight crew before the hijacking.