Two 13-year-old girls were fatally struck by an express train on the Tokyu Oimachi Line in Tokyo’s Shinagawa Ward on Monday evening in an apparent double-suicide, police said.

One of the crew on the train involved saw the second-year junior high school students jump off the platform at Ebara-machi Station together at around 7:20 p.m. They were rushed to a hospital but died shortly after arrival.

According to investigators, the two were wearing their school uniforms and holding onto each other’s arms as they jumped to their deaths.

In their school bags, notes apparently written by the girls were found saying they had “wanted to die,” investigators said. The bags were found on the tracks and the platform.

The notes mentioned suffering over personal relationships but did not indicate whether they had been victims of bullying or other abusive treatment, the investigators said.

Suicides occur on the capital’s railway system on a nearly daily basis but the tallies for each line are seldom released.

The two girls had attended classes as usual Monday and were believed to have left shortly after 6 p.m. after engaging in club activities together.

The train that struck the girls was bypassing Ebara-machi Station on an express route from Mizonokuchi Station.

None of the train’s passengers or staff were injured, according to Tokyu Corp. About 53 trains were suspended on part of the line for roughly two hours, affecting some 16,000 passengers.

A relative of one of the girls expressed shock at the apparent suicide.

She “enjoyed her extracurricular activity at school, and had shown no strange signs over the Golden Week holiday,” the woman told reporters Monday night. “She went to school today as usual. I don’t know why this happened.”

A man in the house of the other girl only said through an intercom that he could not talk at the moment.

A woman in her 40s who is a neighbor to one of girls said she was the youngest of three sisters and described her as a “shy but very good girl.”

“I didn’t notice anything unusual about her lately,” the woman said.

On Tuesday morning, many students at the public junior high school they attended arrived with worried expressions on their faces.

School officials declined to comment.