How to check if thread is killed or keep running when you stop the tomcat Server?

I have a thread pool of 10 threads to serve some task and they are keep running in my web application in tomcat server. I am using the ExecutorService to create Thread Pool as given below.

ExecutorService executor = Executors.newFixedThreadPool(10);

Will these thread be killed or keep running after stopping the tomcat server without executing executor.shutdown()?

Thanks.