A helicopter and emergency response crews could be seen at Chicago's North Avenue Beach on Sunday morning, video showed. Around 11:45 a.m., video posted to social media showed a large emergency response at North Avenue Beach in the city's Lincoln Park neighborhood. Several fire trucks and at least one ambulance responded to the incident. It was not immediately known what prompted the response, though crews could be seen searching the water and on the beach. Video: Citizen App #chicago #rescue #lincolnpark #lakemichigan