EL PASO, Texas -- Hundreds of students and their parents are mourning the loss of Andress High School Band Director Joshua Coleman, 30.

It had been reported that Coleman fell out of bed and hit his head Friday night. But his girlfriend told KFOX that a medical examiner found Coleman suffered a pulmonary aneurism, causing a heart attack.

Coleman's band pulled together to give one final marching performance in honor of their beloved teacher and mentor Saturday.

"The last thing that Mr. Coleman told us was to not quit," said Drum Major Derrick Smith. "He told us that he was ready for tommorow. And with that in all of our hearts and minds, we just decided we were going to go to the New Mexico State University tournament of bands, perform and kick butt."

Coleman died at home following the band's performance at a football game Friday night. That was the last time any of the band members saw Coleman.

"I was thinking, 'Wow, this can't be happening.' My mom had to repeat it to me over and over again to get it through my head that he had passed away," said Smith.

"It was a shock to all of us," said Veronica Dominguez, president of the Andress Band Boosters.

Several of his students said, on the field, Coleman demanded perfection.

"This man spent countless hours in the band room," said Dominguez. "His typical work day was from 6 in the morning until about 11 at night in that band room. He was always there."

Coleman transformed the band, developing their talent and bringing out the best in each student.

"His life was these kids," said Dominguez. "He said he didn't have one child, he had 100."

Off the field, Coleman was known as a jokester with a down-to-earth personality.

"I'm going to miss him a lot," said Smith. "Not only as my band director, but as my friend and as my big brother."

The band's final show, depicting the rise and fall of Rome, was by many accounts its best yet. As for the students, the performance proved to be cathartic, many hugging and crying afterward.

"I know that he's still there," said Smith. "I know he's still watching us. He's sitting in the stands or watching from up above."