[Great68]

So what I've picked up in this situation:

- Air Traffic Controller was working alone
- Just prior to the incident, the ATC was dealing with another plane that declared an emergency, which is what the firetruck was dispatched to
- Air Canada plane given permission to land
- Fire Truck given permission to cross runway as plane was landing
- Was night time and rainy, so truck would not be able to see down the runway very well
- ATC realized the mistake, tried to call the truck to Stop but was too late.