ROCKY HILL, Conn. (AP) - State police say a crash on Interstate 91 in Rocky Hill involving motorcycles and a tractor-trailer rig has killed two people.

The accident occurred near exit 24 in the northbound lanes around 8:20 p.m. Sunday and shut down that side of the highway for nearly six hours.

Troopers say the two motorcycles were speeding and one of them smashed into the back of the tractor trailer, causing all three vehicles to collide.

State police say the drivers of both motorcycles died. They are being identified as 33-year-old Robert Ramkissoon of Windsor and 34-year-old Kevin Williams of East Hartford. A passenger on one of the motorcycle is hospitalized with serious head and back injuries.

Authorities say four other people died in car accidents in Connecticut over the Fourth of July holiday weekend.