Thomas McGlynn and his girlfriend, Patricia Koesterer, had spent the evening at a gin-and-beer party in a dormitory at Catholic University. It was 1 a.m., and they decided to get some air.

They walked up a narrow stairway leading to the roof of Gibbons Hall, a five-story gray stone building, and McGlynn decided to climb up to the top of one of the dormitory's four castle-like towers.

Koesterer, who had remained behind on the gravel roof of the building nervously watching her boyfriend wobble his way to the top of the turret, beckoned to him to climb down.

As McGlynn started back, he fell, hit a wall around the tower, and toppled over the edge of the roof, plunging 65 feet to the grass below.

Miraculously, he was not killed.

The 19-year old youth was rushed to Washington Hospital Center where he was in serious condition yesterday with multipe injuries, including a skull fracture, laceration of the liver, several broken ribs and a fractured collarbone.

Yesterday, students, relatives and friends gathered outside Gibbons Hall and talked about the fall.

"It's a place where the male students prove how brave they are by climbing from the roof of the extension," said one student. "It's done all the time."

Students said university officials have tried to keep locked the door that leads to the roof, but said students break the locks. The lock was broken at the time of the incident, D.C. police reported.

"We want to keep them off the roof," said the Rev. Leo Foley, "but there's a dandy view from there." Foley said he himself watched the Fourth of July fireworks from the roof.

Foley and students said there were several parties on campus Friday night, which launched the first weekend of the new school term.

Chris Manns, a 20-year-old sophomore who was one of the first to reach the scene after McGlynn's fall, said "it was an ugly sight."

"Someone came in the hall and said this guy had fallen off the roof. I thought it was a joke," Manns said.

Manns said students put coats on top of McGlynn to keep him warm until an ambulance arrived."Everyone was praying that he would be all right."

Father Foley administered last rites as the medics hastily worked on McGlynn.

Klair McGlynn, the victim's sister and a Catholic University senior who had been up all night at the hospital after the incident, said her brother is an art major at the school.

"It's a miracle that he is alive," she said.

Throughout Regan Hall, a girl's dormitory where Klair lives, there were handwritten signs yesterday that read, "Tommy McGlynn is going to be all right. He's out of surgery in ICU. The doctors are happy with his progress. No brain damage can be found. Thank you all for your prayers and concern."

McGlynn's parents and an uncle drove from their Wales, Pa., home to be at his bedside early yesterday. Several university officials also were at the hospital.

A hospital spokesman said McGlynn, who come from a family of 10 children, suffered no broken back nor paralysis. She said it is too early to determine if there was any brain damage.