He had already done everything he should, and the old man's condition had already stabilized too. He just had to wait for the ambulance to arrive.
A short while after Lucas left, a red Maserati pulled over at the roadside, and a young woman in her twenties opened the car door and frantically dashed out. While yelling 'Grandpa', she rushed toward the crowd and leaped toward the old man.
"Grandpa, are you alright? Your heart rate monitor app showed large fluctuations in your heart rate just now. I was so scared!" The young woman's eyes were red, and she seemed on the verge of tears.
Her grandfather had a serious heart disease, so there would be people taking special care of him all the time. But today, he suddenly said that he wanted to go out to meet some old comrades in arms and thus walked around on the streets nearby. But he had a heart attack soon after he left.