More than 40,000 Massachusetts electric customers remain without power after last weekend's snow storm.

NStar was reporting nearly 31,000 outages early Tuesday, with Duxbury, Marshfield and Plympton among the hardest hit communities. The utility says it could be Thursday night before some get the power back.

National Grid was reporting more than 9,000 outages, with Scituate and Pembroke the towns with among the highest rate of customers without juice.

National Grid says more than 850 crews are working on the South Shore, and are being hampered by severe damage to lines and equipment, access challenges posed by snowdrifts and unplowed and narrower-than-normal streets.

Crews from 26 states and from Canada have arrived to assist and the utility expects to have all its customers back on line by Tuesday night.