Vin Diesel gets emotional at Paul Walker crash site (VIDEO)

Paul Walker's Fast & Furious co-stars are struggling to cope with the death of their friend and colleague. After attending a private memorial service Monday night in Santa Clarita, Calif., where Walker died in a car crash on Saturday, Vin Diesel, 46, went to the scene and made an impromptu speech in Valencia using a sheriff's car's microphone.

Describing Walker as his "brother," Diesel thanked fans. "At this hard time his family gets to see all of you show the love that you've shown Paul. It's going to stay with me forever," Diesel said. "I just wanted to say thank you. Thank you for coming down here and showing that angel up in heaven how much you appreciate him."