Two motorcyclists were killed Tuesday in a wreck that tied up traffic on State Street for nearly three hours during rush hour. They became the 10th and 11th motorcycle deaths in Ada County this year. A mangled yellow Honda Shadow motorcycle, plastic debris, and broken glass littered the road as police investigated. They said it appeared a speeding eastbound motorcycle had slammed into a white Toyota Scion as it was turning onto State Street from 31st Street, Boise police spokeswoman Lynn Hightower said. The female passenger on the motorcycle was pronounced dead at the scene. The bike's driver suffered massive head injuries and was rushed to a hospital, where he later died. Neither was wearing a helmet. The 63-year-old man driving the Scion was hospitalized with injuries that were not life-threatening, Hightower said. The names and ages of the people involved in the crash had not been released late Tuesday. The wreck happened around 4:45 p.m. west of Downtown Boise, and a small crowd gathered. The motorcycle passenger's body remained covered with a white sheet in the road for more than an hour and State Street did not reopen until about 7:30 p.m. No charges have been filed in the crash, and it could be some time before police determine fault, Hightower said. "Right now, it's just a double tragedy," she said. In an interview with the Statesman earlier this month, Ada County Coroner Erwin Sonnenberg said he is compiling a report on motorcycle deaths and that he believes this year has been the deadliest for Ada County motorcyclists. Thirteen motorcycle deaths have been listed in Ada County so far in 2006, but that includes two people who died in Ada County hospitals from injuries suffered in Canyon County crashes. Sonnenberg could not be reached for comment Tuesday night. Idaho does not require motorcyclists 18 and older to wear helmets and is one of 26 states with only a partial helmet requirement, according to the Insurance Institute for Highway Safety. Twenty states and the District of Columbia require all motorcyclists to wear helmets, and four states have no helmet law.