Listening to ATC sound like controller was working alone (I read somewhere he was the only controller on duty and manning ground and tower?) overloaded and dealing with another accident (a united aircraft with smoke that couldn’t get to a gate). He ends up having to make multiple calls and spending significant time to get the united flight sorted as they claim the situation is worsening, seems true fire truck is sent out as a precaution because there’s no gate or stairs available. An aircraft also makes a wrong turn that he’s dealing with. Another aircraft also reports smelling the fumes. He’s told the jet with fumes needs to get their airline to contact for a gate, then the jet says attendant are feeling sick and upgrades to an emergency. He makes 3-4 calls back and fourth and cannot get a gate or stairs before the truck is called as a precaution. The whole radio is a chaotic chatter being juggled by one controller, even after the collision lots of aircraft are asking questions and making comments instead of clearing the airwaves. He is getting so much information and dealing with so many things. Seems to indicate yet again that staffing issues are decreasing safety at airports.
You could already argue that something had gone wrong before the crash as it sounded like the ATC was almost not able to function. One person was overloaded and the collision happened because the fire truck crossing the runway and the landing Air Canada jet were far down the order of a list of multiple things happening on the airfield that one person simply cannot manage. It was a byproduct of an already breaking operation.
Even without the collision you’ve got an aircraft reporting fumes and people onboard feeling sick and unable to get anywhere to deplane or get air stairs. Thats why the truck was send out. This really isn’t an acceptable level of operations at a major airport like LaGuardia and I think it’s hard to blame the controller here over a broken system.