Authorities are investigating the cause of a bizarre incident on Bakersfield Street last week involving dozens of birds that fell dead or dying from the trees. A cat also died after apparently interacting with them on the quiet sidestreet near Uphams Corner.

The Animal Rescue League of Boston said members responded to 33 Bakersfield St. last Thursday morning after a resident called regarding her sick cat and a disturbing scene as birds dropped from branches and flopped on the sidewalk. Forty-seven Grackles — large, black, perching birds — “were either falling to the ground, sick, thrashing and unable to fly, or were found unresponsive,” the rescue league said in a statement on Friday.

Though given emergency medical treatment, the cat could not be saved, according to the rescue league.

The city’s Inspectional Services Department (ISD) said in a statement on Friday afternoon that inspectors believe three cats may have been affected as well.

Of the Grackles, 12 were found deceased on scene, eight died shortly after rescue on their way to the shelter, and 12 were humanely euthanized due to their poor condition, according to the statement.

Fifteen birds are in good condition and will be sent to Tufts Wildlife Center in Grafton.

Large-scale bird deaths, while rare, have caused concern across the world over recent years. Thousands of seabirds washed up dead on the Alaskan coast earlier this year, but a more eerie parallel to the Bakersfield Street situation occurred in Winnipeg in 2013.

According to the CBC, more than 50 grackles died when they began falling “like raindrops” in the Canadian city’s North End neighborhood. Experts at the time believed the migrating birds had gotten into some sort of toxin, causing the mass incident.

A similar result is possible in Thursday’s case, as Boston Police officers told the Columbia-Savin Hill Civic Association this week that they may have been “poisoned while they migrated here.”

The State Department of Agriculture, the Massachusetts Department of Public Health, City of Boston Inspectional Services Department, and Boston Public Health Commission are working with the rescue league to determine the cause of the incident.

“All animals in various states have been sent to the State Lab for testing,” ISD said, noting the investigation remains active and results were expected later this week.