A 7-year-old boy was apparently killed by two pit bulls kept in a fenced area outside a Massachusetts home, authorities said.

The unidentified boy was attacked Saturday after investigators believe he slipped into the penned area where the dogs were being kept outside the home in Lowell, the Boston Globe reports, citing a statement from the Middlesex district attorney’s office.

Witness David Swiniarski, 22, told the newspaper that he and his roommate ran to the home on Clare Street after hearing the blood-curdling screams down the block, joining a crowd of about 15 onlookers in front of a fence. Swiniarski saw two pit bulls dragging the boy, one by the neck and another by his legs, he said.

“He was already gone as soon as we got there,” Swiniarski told the newspaper.

Roger Rodriguez, 56, and his girlfriend, Jean Remon, 45, said they saw the boy playing outside with a group of children earlier in the day and later saw his body covered by a white sheet in the driveway. The girlfriend of the dogs’ owner had repeatedly warned the kids to stay away from the animals, Remon said.

“I told them a month ago not to jump the fence,” Remon recalled the unidentified woman saying.

Two people declined to comment when reached by a reporter at the boy’s home, which was identified by neighbors.

“There’s nothing to say about it,” one woman who answered the door at the home told the Globe.

Giovanni Miranda, 28, said the boy seemed to love animals, as he was “always trying to pet a dog.” He frequently rode his bike through the neighborhood and was a friendly boy, Miranda said.

“There can’t be anything worse than to lose a 7-year-old to a dog,” Miranda told the newspaper.

Meghan Kelly, a spokeswoman for the district attorney’s office, told the Globe in a statement that they were investigating the death. The boy’s name will not be released and no charges had been filed as of Sunday, she said.

One of the dogs was shot at least once by police. The second animal was taken into custody by animal control officers, the Globe reports.

The severity of the attack was clear in the voice of a police dispatcher as she sent officers to the scene, according to a recording by Broadcastify.com cited by the Globe.

“We are getting reports from Lowell [police] that the child is being attacked by multiple dogs at that location,” the dispatcher said. “And they are not letting up.”