Gina Gentile and Vanessa Dorwart may have been part of a suicide pact with a group of teenagers, police told family members -- and that Gentile and Dorwart may have kept that pact Thursday morning.

Dorwart and other girls agreed to show up Thursday morning at the Norwood train station to end their lives together, a source tells NBC Philadelphia.

Gentile, Dorwart and a third Interboro High School girl, Kelly Cashwell, all left school Thursday morning, according to school officials.

The three girls were seen by a SEPTA ticket agent yelling or arguing on the southbound train platform, and one of them was talking on a cell phone, just minutes before Gentile and Dorwart were fatally struck at 10:28 a.m. by a high-speed Acela train coming up from Washington, D.C.

How many more teens may have been part of the alleged pact is still unknown. Cashwell was cooperating with police and remains in crisis counseling.

The night before the girls' deaths, several teens gathered to share stories and poems about their lost friend, Bradley, Gentile's grandmother told the Inquirer.

The cell phones of Dorwart, 15, and Gentile, 16, were found intact at the scene, and police were sending the phones to a forensic lab to see the last texts the teens sent before they died.

Family and friends told NBC Philadelphia that Gentile was heartbroken over the recent death of her boyfriend. The Interboro High School sophomore was dating 17-year-old Bill Bradley for a year when he was struck and killed by a car while biking over to see her on Jan. 19, Gentile's grandmother, Rosalia Giordano, told the Inquirer.

"Bill. Life without you here is not going to be the same," Gentile wrote on the "R.I.P. Bill Bradley" Facebook page. "Save a spot for me Pumpkinn."

Dorwart, too, was saddened by Bradley's death, and seemed to be in turmoil about the end of a recent relationship, according to her postings on Facebook.

"idont wanna walk this earth if igotta do it solo, you usta be my rida. - kus iwas so high and now im so low and i dont wanna walk around on my own," Dorwart wrote 10:10 p.m. Tuesday.

A little less than an hour before she had written, "ijus wanna be happy again. not the fake smile my real one."

Paul Dorwart, Vanessa's father, told the Inquirer that the two of them were happily planning her 16th birthday party the day before she died.

"I don't know what changed from 11:30 [the night before] to 10:30. She didn't leave anything. She didn't say goodbye," Paul Dorwart said.

"I'll never see her smile again. I'll never see her beautiful blue eyes. My heart just got ripped out, and I don't know why."

Funeral arrangements have been set for Dorwart . Viewing will be from 5-9 p.m. March 5 at the McCausland-Garrity Funeral Home (202 S. Chester Pike, Glenolden, Pa.)

The funeral will be held March 6. There will be a viewing from 9-11 a.m. at St. Gabriel's, followed by the funeral (233 Mohawk Ave., Norwood, Pa.)

No funeral information has been released yet for Gentile.