Health officials are trying to figure out what caused a large flock of birds to fall out of the sky on Thursday over Boston's Dorchester neighborhood.
Inspectional Services told WFXT that 47 songbirds were found on the ground or falling from trees. Two cats in the area had also become sick.
Fifteen of the grackles ultimately died. The cats had to be euthanized.
The Animal Rescue League of Boston said it went to the neighborhood after residents reported birds falling from the sky. They have launched an investigation into the deaths.
The birds that died will be sent to Tufts University in Medford for testing.
"More will be revealed when the tests come in," the Boston Inspectional Services Department said. "It could have been done innocently, I don't want to think that someone is doing this intentionally, but we're asking the whole neighborhood that, if anyone sees anything out of line, dial 311."
The Associated Press contributed to this report.