he shot 30+ kids, so 40 minutes probably accounted for a lot of the death due to bleed out.
They were slack in Sandy Hook too, no triage, no wounded, all who were shot were dead. They never talk about if they learned anything from that. They never learned from the Florida shooting either, allowing the killer a lot of time to accomplish his task.
Of course we have a problem with security, but the Police have been neutered. Instead of them being taught how to descalate situations, we need them to be given essentially free rein. The innocents lost by aggressive policing, pales in comparison to those save.
I heard it was an hour between when he started shooting kids and when they shot him. So yeah, many bled to death.