Massachusetts hospitals are buckling under growing financial strains, with 16 - nearly a quarter of them - losing money last year, according to a new state report. Thirteen hospitals in the state also suffered losses in 2009, but the deficits at many of them widened in 2010, the report from the state Division of Health Care Finance and Policy showed. Thirty others managed only modest profits last year. Healthcare professionals say the financial squeeze is likely to tighten - especially for community hospitals and those that treat low-income patients - as Medicare and Medicaid payments are reduced. Reimbursements from such public payers account for about 60% of revenue at the average Massachusetts hospital.