 Make sure you stay hydrated and cool this afternoon. All lanes at times are blocked in Sun Valley as a crash on the 5 North between Sheldon Street and Highway 170 is causing stop traffic from Sunland Boulevard over 30 minutes. To avoid further delays, you might want to use San Fernando Road or Glen Oaks Boulevard as your alternate. In Selmar on the 5 North after the 210, watch for a separate accident in the right lane causing heavy traffic from the 405.