CHESTER, Calif. -- A mother is dealing with a double tragedy after her daughter is killed during a weekend prom date and her son is severely injured in a wreck.

Jennifer Carrigan and Steven Furtado were found dead Sunday by Carrigan's mother at a house in Chester, about 90 miles northwest of Reno. Both were 18.

When told of his sister's death, 20-year-old Billy Carrigan headed home from Berkeley. Shortly before 7 p.m. Sunday, just before he reached Chester, Billy Carrigan crashed his Toyota Tacoma pickup truck into a stand of pine trees along Highway 36.

A spokeswoman at Enloe Medical Center in Chico said he was in critical condition.