Police have not released a formal statement at this time about the crash, which happened just before 4:30 p.m.
Traffic was stopped at the crash site so the victim could be airlifted for treatment. However, especially heavy traffic volume due to rush hour, compounded by traffic heading to various events – the Merrimack Premium Outlet grand opening weekend, Merrimack's Rock'n Ribfest, and the closing weekend of New Hampshire Motorcycle week – have left the area in gridlock.
State Police have urged the public to avoid the area completely until traffic is restored to normal ebb and flow.
This is the fourth fatal motorcycle accident reported today, with three others earlier in Dummer, Nelson and Laconia.
UPDATE, 5:38 P.M.
Resident Kathy Peterson reports "our highway is a mess right now," after exiting the Everett Turnpike at Exit 5 South.
The initial back-up was caused by a motorcycle accident at Exit 8 northbound, which has been compounded by a second accident – a three-car crash at Exit 6, Nashua Fire officials confirmed.
No one was injured in that crash.
"People are jumping off the highway at Exit 7 just to get off and now they're backing up on Amherst Street," Peterson said.
The accidents happened during an already busy traffic weekend, with the opening of the Merrimack Premium Outlets, at Exit 10, the Rock'n Ribfest, which started at 4 p.m., also in Merrimack, and residual Motor Cycle Week/weekend traffic.
State Police said the highway is backed up for miles, and urge the public to stay off the highway and main arteries feeding on and off the turnpike.
"There are cars and trucks with boats and trailers trying to head north for the weekend, all stalled in traffic across three lanes – what a mess," Peterson said.
UPDATE, 5:10 p.m.: The Everett Turnpike northbound has been reopened to one lane as of 5 p.m. following a serious motorcycle accident that forced its closure to allow a medical helicopter to land.
Merrimack Police Chief Mark Doyle said the initial closure rerouted rush hour traffic off of the highway at Exits 8 and lower as traffic backed up quickly on the highway.
Though the highway is partially open, Doyle cautioned people to seek alternate routes if they can until the highway is fully re-opened. It is unclear how long that may take.
Troopers who were initially stationed at Exit 10 to handle traffic going to the Merrimack Premium Outlets grand opening and Rotary Club of Nashua West's Rock'n Ribfest, were transferred down to handle traffic at the scene of the accident.
Original story: Emergency personnel are at the scene of a serious motorcycle accident on the Everett Turnpike in Nashua.
The crash was first reported around 4:20 p.m. in the northbound lane, between exits 8 and 10, according to emergency radio broadcasts. A rider was reportedly down and unresponsive.
A medical helicopter has been called in, and the landing zone is expected to be just south of Exit 8. A portion of the highway is reportedly closed to allow the helicopter to land. The accident has also caused police to re-route traffic headed to the Merrimack Premium Outlets, which opened Thursday.
This is one of at least eight motorcycle accidents reported across the state today. This is the final weekend of Laconia Motorcycle Week 2012, which draws bikers from all over the country.
Nashua Patch will have more on this story as it develops.