Health officials might know this week what caused 47 birds to fall from the sky in an area of Dorchester. 

Twelve of the birds, identified as grackles, have died and 35 were found alive in various conditions, said Lisa Timberlake, director of publicity with the city's Inspectional Services Department, in a statement.

Grackles are a member of the blackbird family. Timberlake said that many of the alive grackles were lying "almost motionless on the ground" while some were able to fly with difficulty and others only able to "walk or stumble." 

The Animal Rescue League, along with Inspectional Services, Environmental Services, and the Department of Public Health, launched an investigation into the incident, which focused on birds found on or near Bakersfield Street in Dorchester. 

Willien Pugh, 67, who lives on Bakersfield Street, first reported the incident to the city, according to the Boston Globe, after her outdoor cat had become sick and died. She described the birds as “lethargic, trying to roll over, not able to stand up or fly.”

City officials immediately started looking for a cause, from a virus to environmental poisoning and even possibly something intentional, according to NECN

Timberlake said that the city believes three cats in total may have been affected as well. 

Investigators do not believe there is any danger to humans, NECN added, but they are warning pet owners to watch out for what their pets put in their mouths while outside.

All animals in various states have been sent to the state lab for testing, according to Inspectional Services.