Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_30 ( tonnage__grt_ INTEGER, time VARCHAR, casualties VARCHAR )

### Question ###
What is the sum of tonnage with a time at 00:10 and less than 42 casualties?

### Accurate SQL ###

SELECT SUM(tonnage__grt_) FROM table_name_30 WHERE time = "00:10" AND casualties < 42