While waiting to get into the air at DFW tonight, I noticed quite a few Fire, EMS, and police units following an aircraft as it taxied to terminal D. I mean, I wouldn't start a new thread on here if it were two fire trucks and an ambulance; there was a huge response to whatever was going on. The plane parked on the D30-D40 side of D terminal, and more and more fire trucks, ambulances, and police cars began piling up as it parked at the gate.

The plane looked like a 767 or a 777, but I can't tell for sure. Anyone know what was going on?