Trigger Hell ... HELP!

I have two tables:

table1
field1 = identity
field2 ...
field3 ...
field4 ...

table 2
field1 = identity
field2 = foreign key (table1 field1)
field3 ...

When I delete a row in table1, a cascade delete relationship deletes the appropriate table2 row(s). Since I have a trigger on table2 that updates a few fields in table1 (field3, field4), when I try to delete table1, I get an error. The cascade delete tries to fire off the trigger in table2, which in turn tries to update table1 fields and thus fails. How do I circumvent the triggers from firing?

Triggers look something like this:

CREATE TRIGGER trg_delete_table1_field3_field4
ON dbo.table2
FOR DELETE
AS
BEGIN
DECLARE @newField3Value as money
DECLARE @newField4Value as money
Set @newField3Value = (SELECT SUM(field3) FROM table2 WHERE key = (SELECT key FROM deleted))
Set @newField4Value = (SELECT SUM(field4) FROM table2 WHERE key = (SELECT key FROM deleted))
UPDATE table1
SET field3 = @newField3Value ,
field4 = @newField4Value
WHERE key IN (SELECT key FROM deleted)
END