A small town in Iowa is stunned but pulling together after a school shooting in which a 17-year-old killed a sixth-grade student and wounded seven other people before authorities say he died of a self-inflicted gunshot wound. Many questions remain about how the shooting unfolded and what might have led up to it, but a few details have emerged.

According to authorities and school officials, a teenage student armed with a pump-action shotgun and a small-caliber handgun opened fire at Perry High School just after 7:30 a.m. Thursday, shortly before classes were set to begin on the first day back after winter break. Iowa Division of Criminal Investigation spokesman Mitch Mortvedt said the shooting started in the cafeteria, where students from several grades were eating breakfast, then spilled outside the cafeteria.

The student who was killed, 11-year-old Ahmir Jolliff, was shot three times, though details about where he was at the time have not been released. Perry High School Principal Dan Marburger and six others, including two staff members and four teenage students, suffered injuries ranging from significant to minor. The high-schooler identified as the shooter, Dylan Butler, died of an apparent self-inflicted gunshot.

Butler also had what authorities called a “rudimentary” improvised explosive device that was safely disarmed.

Police said they believe Butler acted alone.

While authorities have said little about what happened inside the school, some stories of bravery and selflessness have begun to emerge.

Authorities have said Marburger, who has been principal since 1995, put himself in harm’s way in an apparent effort to protect students. Perry Superintendent Clark Wicks said Marburger was a “hero” who intervened with Butler so students could escape. Wicks said other staff also acted heroically, including Middle School Assistant Principal Adam Jessen who “carried a wounded student into a safe area.”

The principal’s daughter, Claire Marburger, posted on Facebook Friday night that cards were coming in from community members and students. She said her favorite, which made her and family members laugh and smile, read, “not all heroes wear capes, some are the school principal.”

One mother, Bobbi Bushbaum, posted on Facebook that her son Corey was shot multiple times, but was able to stumble to a nearby field. When she arrived, she saw him being helped toward an ambulance by others, whom she thanked, saying: “I would like them to know my son wouldn’t be here without them.”