Fitch Ratings downgraded two classes of Credit Suisse First Boston Mortgage Securities this week, citing 24 loans as being "of concern." Nine of those are specially serviced loans. Two of the main risks include a specially serviced loan secured by six industrial properties in Michigan, Ohio and Indiana, which transferred to special servicing in August 2010, and a second loan secured by a 273-unit apartment complex in San Antonio, Texas. The loan secured by industrial properties was moved into special servicing last August on a threat of imminent default. About three of the properties are fully vacant, while three others are 100% occupied. The special servicer accepted a deed-in-lieu of foreclosure deal and is expected to gain title to the properties in the near future. Overall, Fitch downgraded the two classes of securities while affirming 14 other classes. Fitch said the downgrades reflect modeled losses on 4.13% of the remaining pool. By July of this year, the pool's aggregate principal balance was cut by 28.8% to $843.5 million from $1.19 billion at the time of issuance. Write to Kerri Panchuk.