11.   Government experts say they do not know if tire problems are worse now than before, because the surveys are the first of their kind.

12.   He said he would have ordered an immediate, broad investigation if anyone had told him of the tire problems.

13.   He said he would have ordered an immediate investigation if anyone had told him of the tire problems.

14.   He was having tire problems.

15.   House investigators showed reporters a Firestone financial statement indicating that the tire maker had found a pattern of tire problems earlier than the company has admitted in the past.

16.   It turned out that the tire problems were clustered in Texas, because the failures are linked to prolonged high-speed driving in hot weather.

17.   On Thursday, a government agency in Venezuela is expected to issue a report criticizing both Ford and Firestone for the way that they handled tire problems there.

18.   Regulators are still investigating accidents reportedly connected with the tire problems.

19.   Recent accident data and investigations into tire manufacturing problems have kept the subject in the forefront of automotive news.

20.   The acknowledgment was unusual for a company that has been criticized for not having its top executives actively address the tire problems.