I just experienced a situation at EWR, and I feel it is good to share.
We were traveling from EWR to TLV with ELAL. When we were sitting on the plane, I noted that my (very important!) laptop was not with me.
I went to the crew, and they were already preparing to close the doors. They were nice enough and called someone to take me out and said that they are giving me 45 seconds to be back, and if I was not back, they are leaving. We ran out and searched till the TSA counter, but nothing was found, so we ran back, and I caught the flight on my last breath. (Honestly, I don't remember running so fast in my entire life)
I was nervous about my laptop, and everyone I spoke with told me I have no chance. But I decided to give it a chance, as I need all my information on it. When I arrived in Israel, I searched all the options and started to fill out claims here and there wherever it was possible, from TSA claims to EWR lost and found. Not that I had high hopes; I just wanted to feel that I tried my best.
On our 7th day in Israel, I got an email from TSA that they had found a laptop. But my laptop didn't have a name on it, so I wasn't at all sure if they had found mine.
Shortly after I came back, I drove over to the address they provided, about a 30-minute drive from the airport, and yes, the laptop was mine! BH
My takeaway from this is first Daven to Hashem. Then follow all the options you have.