ROCKPORT — A helicopter carrying six large lead acid batteries to a Verizon cellphone tower atop Ragged Mountain spilled its payload sometime Tuesday, causing most to explode and some to catch on fire on the slopes.

A responder from the Maine Department of Environmental Protection went to the scene Tuesday and Wednesday, finally locating the lost and destroyed batteries Wednesday afternoon, according to Director of Communications Jessamine Logan.

The accident happened when a pallet rigged beneath the helicopter to carry the batteries, which each weighed between 100 and 120 pounds, failed and lost all 700 pounds of material, she said. One of the batteries was found partially intact because it landed on thick peat moss. The rest exploded, and three caught fire, with a total of 68 pounds of sulfuric gel lost on the mountainside.

“This is definitely an unusual one,” Logan said. “There was quite a big affected area. I would say that it’s fortunate that these fires didn’t spread.”

She did not know who was piloting the helicopter or what organization would be responsible for the cleanup. Clean Harbors, a company that provides hazardous waste disposal, was expected to arrive at the scene Thursday to clean up and test the soil.

Exposure to sulfuric acid can irritate and burn skin and eyes, cause headache, nausea and vomiting and irritate the lungs. It is a carcinogen in humans, according to a fact sheet distributed by the New Jersey Department of Health.

Logan said that the explosions and fires affected an area that stretched 1,000 feet from the impact site. There were still battery pieces in the trees on Wednesday afternoon.

The Camden Snow Bowl is located on Ragged Mountain, but it was unclear Wednesday whether that property was affected by the accident.

Verizon Wireless spokesman Michael Murphy said Wednesday night that the company on Tuesday was able to identify where the batteries had fallen and that the debris was confined to a small area on private property owned by the cell towers’ landlord.

“We immediately secured contractors to conduct a thorough cleanup, which is expected to be completed Thursday, and are continuing to work closely with the Maine Department of Environmental Protection to keep them informed of developments.”

Murphy said that the batteries are used if there is a commercial power outage so that cellphone service will remain uninterrupted.

“We are committed to providing reliable cell service to our customers in rural areas, which is why we go to such great lengths to ensure backup power is available at cell sites,” he said.