My brother found our dead father in the basement

This happened in 2017. My mother had just left my dad for a weekend to go visit her sister. It was supposed to be for 2 days, but she ended up going for 4. My dad and I were in the basement at the time. I was 16, my brother was 18. It was a regular Saturday morning. My dad and I were working on my car, and I was going to drive him to get a haircut. I was working on the timing belt. I noticed the stairs started going up really slow. I said "I think dad's coming". I turned around, and he wasn't there. I thought he was walking to get a drink. A couple seconds later I heard the door slam open, and I turned around to look, and I saw the police officers bursting into the basement. I had no idea what was going on. There was a police car in the driveway, and 2 officers had my brother by the arms. He was trying to push them away, saying "no no no no no no no". I don't know what happened for the next 5-10 minutes, I was in shock. I couldn't say anything. The officers asked my brother where he was going, he said he was going to the store. Then one of the officers noticed something on the stairs, and asked him to go look at it. My brother looked, and started screaming. He ran back upstairs, and went out the back door, and out the front door. The officers went up the stairs. I heard them call 9-1-1, and my brother came back in the basement. He looked at me, and I remember thinking he was about to go hug me. He didn't. He ran out of the basement, and out the front door. Then I started screaming. My neighbor came in the back door, and found me crying. She called 9-1-1. The police came in and found me on the floor, crying. They took me outside, where the neighbor was. They took me to a lady's house across the street, who I've never met before or since. I asked her what was going on, and she said she didn't know, but she asked me if I was okay. She took me into her living room, and let me watch TV until my mom came home. I never heard a word about it. Not until like 6 months later, when I asked my mom what happened that day, and she just told me my dad died from a heart attack. I never got any details, and I never asked again. I'm 20 now, and I still think about it every day.