Check out the International Center for 9/11 Justice.
Why — when she was using the calling card associated with the current phone number of her parents, and that number was written on it — did flight attendant Sara Low dial the long-out-of-service number of her childhood home FOUR TIMES from Flight 11? Was someone else dialing it? Or was she instructed to call her family and did not want to actually reach them? Whatever the case may be, one thing seems clear: The person named Sara Low was not calling her family to report a real hijacking underway on Flight 11. This is just one of the countless problems with the 9/11 phone calls. See here for an in-depth look: youtu.be/QRJnAu0tq8w?si
Start at the 24-mark with Ted Walter.
For more on Sara Low's calls to her childhood home, see here (do a control+F search for Sara Low): archive.li/WgPzj