YONKERS, New York (WABC) --The sole survivor in a deadly car crash that killed his best friend is talking about how a flat tire changed his life forever.
He says he can't cry, he can't yell, he just feels numb.
"I couldn't see anything. I just called his name a couple of times. He didn't answer," said Nana Mensah, crash victim.
Mensah keeps reliving the moment of the crash, the moment he lost his best friend Zachary Dunn.
"It hasn't hit me yet. I've been thinking about it for the whole week, but it hasn't hit me," Mensah said.
The friends were driving home Monday morning from work when they got a flat tire and had to stop along the Saw Mill River Parkway near the McLean Avenue exit in Yonkers.
"There's Nana right here. We just caught a flat in the middle of the highway," Zach said in a Snapchat video.
Zach posted a snapchat video on social media about being stranded on the side of the road.
Nana was sitting in passenger's seat, Zach in the driver's seat, and their two friends were standing on the shoulder when a car hit them from behind.
"I fell asleep. I had my seatback like that. I was leaning back and then the next thing I know I called Zach, he's not answering and some lady pulled me from the car," Mensah said.
A Good Samaritan helped Nana out of the wreckage, but couldn't reach Zach.
The 18-year-old was killed instantly.
Nana is still sore, but does not have any major injuries.
His two other friends were not hurt.
Junior Silverio-Ventura was arrested.
Police believe he and another driver were drag racing.
"The lady was like, 'These kids were racing and I knew this was going to happen,'" Mensah said.
Nana and Zach recently graduated from Palisade Preparatory School in Yonkers.
They were exciting about going to college together.
"That was my right hand man. I was with him every day. Literally, I was with him every day," Mensah said.