protect your belongings. let geico help you with renters insurance. egypt now saying it will accept help from the united states on the metrojet crash investigation. the ntsb will be the first americans directly involved. it appears though that is strictly for the engines which were pratt and whitney. >> a military explosive was likely used to take down the flight. only explosives of that strength could have blown the passenger jet out of the sky. terrorists in sinai have easy access to those types of explosives, including c-4. they've been used in other attacks. how difficult would it be to get them through airport security here in the united states? it is the crucial question tonight. >> reporter: can you spot the explosive? >> that's all it's going to look like to a screener. >> reporter: that is a half