The early morning glare of the sun against wet pavement led to two chain-reaction sets of accidents on Interstate 89 Friday morning.

At 6:43 a.m., emergency crews responded to a report of a motor vehicle crash in the southbound lanes of I89 between exits 2 and 3 in Concord.

“On arrival, companies found multiple rear-end collisions spanning an 800 yard stretch of highway,” the Concord Fire Department said in a statement. “Drivers cited that intense sun glare reflected by the wet roadway was a contributing cause of the accidents.”

The initial accident led other drivers to slam on their brakes, causing a chain reaction of collisions. Concord officials said a total of nine vehicles were damaged or totaled and three patients were transported to Concord Hospital, two with significant injuries.

The southbound lanes of the highway were shut down for 45 minutes, which led to a traffic backup during the morning commute. 

About a half an hour later, as the initial accidents were being cleared, the Hopkinton Fire Department was alerted at 7:17 a.m. to another string of accidents involving drivers headed south about 1.5 miles away from the first crash scene.

“The second accident involved multiple cars with significant damage, including an empty log truck that was struck from behind,” the fire department said. “The bright sun and the sudden braking of multiple vehicles was also cited as a contributing factor in this incident.”

Concord firefighters assisted Hopkinton to extricate one person trapped in a vehicle and transport a second person to the hospital. Like the first accident, the highway was shut down while emergency crews removed vehicles and tended to the wounded. 

Two vehicles were totaled in the second crash and the logging truck sustained “significant damage.”

Concord and Hopkinton rescuers were assisted by NH State Police, Hopkinton Police, the Henniker Fire Department and multiple tow companies.

In total, Concord Fire Department responded with 16 firefighters staffing three ambulances, two engines and one tower truck.