Why was Northern Rock nationalized during Gordon Brown’s government?

Northern Rock was nationalized by the British government in February 2008 during the government of Gordon Brown because the bank had run out of liquid assets amid the financial crisis of 2007–08.1

As the fifth-largest mortgage lender in the United Kingdom, Northern Rock appealed to the Bank of England for a loan to address its liquidity issues. However, news of this bailout triggered panic among depositors, leading to the first bank runs in the United Kingdom in 150 years. Following these events, the government moved to nationalize the institution.1