AMR Corp is having a really bad day. As if UBS today downgrading the equity to sell from neutral wasn't enough, now its subsidiary, American Airlines, is facing a bomb threat.

This morning UBS cut the security's ratings due to rising oil prices, which is likely to keep corporate and leisure travelers at bay. As crude prices flirt with the $100 per barrel mark, airlines are seeing higher-than-budgeted fuel bills.

To drop another bomb on the company, so to speak, AMR subsidiary American Airlines is now facing a bomb threat on one of its planes at LaGuardia Airport. The empty plane, which took off from Chicago, has been isolated and is currently being searched via bomb-sniffing dogs. No one has been hurt.

As a result of the less-than-stellar tidings, AMR investors have sent shares plummeting today. The stock is currently at $20.35, down 5.39%. Earlier today, AMR hit a new annual low of $19.90.