Financial problems began to resurface shortly afterward, and TWA's airline assets were acquired by American Airlines in April 2001. As part of the deal, TWA declared Chapter 11 bankruptcy (for the third time) the day after it agreed to the purchase. The terms of the deal included a $500 million payment. However, since American assumed TWA's liabilities, the deal was estimated to have cost American $2 billion.
Here's the TWA route map at the time of the merger:
After the merger, a pretty decent commercial was put together showcasing both airlines: