A classroom in the Bnos Menachem girl’s school in Crown Heights, Brooklyn. Photo: YouTube screenshot.

A Brooklyn girl’s school is the first in New York City to install special security doors in the wake of a series of mass shootings, including two targeting synagogues.

According to The New York Post, the Bnos Menachem elementary school began the installation last week. The doors weigh 150 pounds and are braced by metal bars. They are made of galvanized steel and can be manually locked from the inside with the turn of a thumb.

Harrington Park, New Jersey School Superintendent Adam Fried, whose schools have installed more than 45 of the doors, said that the thumb lock is particularly important, since “a five-year-old could do it.”

A mother whose daughter attends Bnos Menachem told the Post she was happy with the new security precautions, saying, “I think it’s great. It’s a very secure feeling to know that there’s a security measure and that they’re really thinking about the safety of the children.”

The doors are made and installed by an Israeli company, Remo Security Doors, whose president Omar Barnes said the doors contain bullet-resistant windows. “No weapon will open the door,” he affirmed.

“I was born and raised in Israel. When I hear the siren and go to the safe room, I know that I’m safe, physically and mentally,” he added.

The doors are the first of 90 that Bnos Menachem plans to install, and more than 50 Jewish schools and synagogues are planning to follow suit. The measures are being funded by a $150,000 grant from the Department of Homeland Security.