A sinkhole on I-495 in Haverhill is causing a ‘major impact’ on traffic. State police the sinkhole began forming on I-495 South just after Exit 106 as the result of a water main break.

All lanes on Interstate 495 in a Massachusetts town were temporarily closed Tuesday as part of a construction project.

Two lanes of the highway were closed, but later reopened, Tuesday afternoon, state transportation officials said.

A photo shared with Boston 25 shows the heap of boulders stretching across the two rightmost lanes of the highway.