LITTLETON, Colo. (AP) - He taught them how to type and how to run the fast break. He smiled easily and always saw the good in life. To his young grandson, he gave the best bedtime snacks.

In the end, William ``Dave'' Sanders gave it all, sacrificing his life while trying to save students during the massacre at Columbine High School last week.

``Mr. Sanders,'' student Laurel Salerno said through tears at Sanders' funeral Monday, ``I thank you.''

It took the sanctuary and two overflow rooms at the Trinity Christian Center to hold the 2,500 people - students, teachers, residents - who bid goodbye to the 47-year-old, bearded and bespectacled Sanders. He died of gunshot wounds in the rampage that also killed 12 students. The two gunmen committed suicide.

``He was and always will be a hero in my heart,'' said his niece, Kim Smith, one of many people offering testimonials.

The ceremony for Sanders was one of four funerals Monday, the other three for students.

Mourners remembered Cassie Bernall, the 17-year-old girl who professed her love of God just before she was shot, and Lauren Townsend, an 18-year-old honor student and captain of the girls' varsity volleyball team. A funeral was held later Monday for Daniel Rohrbough, the 15-year-old boy shot while holding an exit door open for fleeing students.

At the funeral for Sanders, students past and present walked to the front of the chapel and stood over his dark blue casket, which was covered in a large flower arrangement, to remember him as a teacher, coach, friend and hero.

As gunfire echoed through the school cafeteria during the attack, Sanders shouted out to students and herded them to safety.

``He was running around and I remember seeing him jumping over the chairs and yelling, `Everybody get down!''' student Lindsay Dowling told mourners. ``I truly believe he saved my life and many other people's.''

Sanders was shot twice in the chest and staggered into a science classroom, where students tore off their T-shirts and pressed them to his wounds. Students pulled out Sanders' wallet and held it open so he could look at pictures of his wife and daughters. The dying words of the father of three daughters were: ``Tell my girls I love them.''

At the funeral, daughter Angela Sanders read a ``letter to daddy'' that praised his heroism and contained a postscript that read, ``The girls and I would like you to know that we love you.''

One of Sanders' 10 grandchildren, Austin Sanders, a preschooler, told mourners he liked to play with his grandfather and ``he always made good bedtime snacks.''

Sanders spent 24 years at Columbine, his first and only teaching job. He taught business and substituted in the science department. He also coached track and girls' basketball and girls' softball.

``He taught me how to run the hurdles,'' recalled a former student, track athlete Chris Black. ``I fell down quite a few times, but he was always there to pick me up.''

As mourners listened to the testimonials, they clutched hands and wiped tears. Students gathered in small groups, embracing each other. Most in the crowd wore the now-familiar ribbons in blue and silver, the school's colors.

``Dave on Tuesday bled the ultimate blue and silver,'' said Columbine High teacher Joe Marshall. ``He will never, never be taken from us.''

Other funerals Monday:

- At the West Bowles Community Church, about 2,000 people remembered the strong Christian faith of Miss Bernall. Other students had said after the rampage that when one of the gunmen asked her if she believed in God, she answered that she did. The gunman then killed her.

``Cassie's response does not surprise us,'' the family said in a statement released at the funeral. ``Her life was rightly centered around our lord Jesus. It was for her strong faith in God and His promise of eternal life that she made her stand.''

Pastor George Kirsten told mourners: ``Cassie died a martyr's death. She went to the martyr's hall of fame.''

- About 1,200 people packed into the standing-room-only worship area of Foothills Bible Church to mourn Miss Townsend. The Rev. Bill Shelby asked the audience to use the tragedy to become the best they can be and love all types of people as Lauren did.

Her freckled, smiling face beamed down on the crowd from two large screens in the church. Friends and family recalled a motivated, somewhat shy senior who wanted to become a biologist like her brother Matt.

``People say that Lauren was a victim,'' said Matt Townsend, 25. ``I don't think of her in that way. The ugly thing that happened last Tuesday, they couldn't conquer her beauty.''

Miss Townsend was a volleyball player, member of the National Honor Society and candidate for valedictorian.

``She was really a remarkable girl,'' her uncle, Harvey Gates, said before the service, wiping away a tear.

Friends and family wrote their farewells in blue and black marker on Miss Townsend's white coffin. ``I miss you,'' said one.