Complex sentence: Jack narrowly escapes from the house before it explodes, as this happens, Phillip sends a couple of his men to attack Marilyn and Milo (who was in the CTU van with Marilyn).
Split into simpler sentences: Jack narrowly escapes from the house before it explodes. As this happens, a couple of Phillip's men pursue and attack Marilyn and Milo (who was in the CTU van with Marilyn).