Plague Heart with sprinting zombies

Hey all. So this is my 2nd playthrough on Dread. I've noticed a serious difficulty spike from my first normal playthrough.

I've lost 2 citizens trying to get to a plague heart that is also giving zombies sprinting powers and increased awareness.

I've tried two methods:

1) pulling up outside of the plague heart building - instantly swarmed, had to retreat, citizen died.

2) park about 400m away and slowly fight my way to the building. Same result. I got swarmed, citizen died.

It seems like they respawn. Doesn't matter how many you kill they just never stop coming. Is the only way to handle this some kind of kamikaze mission. I'm lost.

EDIT: I've also tried using my vehicle to thin the herd, but there are so many zombies that my car quickly falls apart.