Dunn, 480 U.S. 294, 301, 107 S.Ct. 1134, 94 L.Ed.2d 326 (1987); French, 291 F.3d at 951-52. But the defendants have probably waived the argument, since they have not contested Nail’s characterization of the yard and porch as curtilage. In any event, the question of “curtilage” is really beside the point because the 911 call gave the officers all the exigent circumstances they needed. Nail’s “reasonable explanation,” which he has admitted was a lie, was not the end of the encounter. Olmstead then failed to appear at the door as requested, Nail disappeared, and the officers heard the back door slam. These events made it reasonable for the officers to believe that Nail was fleeing or Olmstead was potentially in danger. See, e.g., United States v. Elder, 466 F.3d 1090, 1091 (7th Cir.2006) (<HOLDING>); United States v. Najar, 451 F.3d 710, 719-20
holding that officers warrantless entry was justified to assure safety of person who called 911 holding that 911 call reporting domestic dispute and child telling officer that a man with a gun was inside fighting with her mom constituted exigent circumstances that justified warrantless entry into home holding that exigent circumstances justified warrantless entry where officers were faced with a call reporting burglary in progress holding warrantless entry of residence was justified by need to search for intruders or injured occupants holding that the police officers had probable cause to make a warrantless entry