Two people were injured, one seriously, in a three-vehicle crash involving a tractor-trailer on Interstate 95 in Newburyport on Sunday night, said Massachusetts State Police. The tractor-trailer, a pickup truck, and a sedan crashed on I-95 South around 7 p.m. near the Whittier Bridge, said State Police Lieutenant Dan Richard. A male passenger of the sedan was thrown from the car and had to be airlifted to Beth Israel Deaconess Medical Center in Boston. The sedan’s driver, a female, was taken to a local hospital, Richard said. The identities and conditions of the victims were unknown Sunday. Richard said police were investigating the crash. “There were three vehicles involved, and they all contacted each other at different times, but we don’t know who hit who first,” he said. The two other vehicles’ drivers were uninjured, Richard said. The northbound and southbound lanes of I-95 were closed, clogging traffic for about an hour.