Caldwell, Alden Gates, 81, of Largo, died Friday (Dec. 18, 1992) at Largo Medical Center Hospital. He was born in Bangkok, Thailand, and came here in 1977 from Allentown, PA. He was a chemical engineer and worked 32 years for Leigh-Portland Cement Co., Allentown. He was a Presbyterian. Survivors include a cousin, Dorothy Tieljen (1), Largo. Moss Feaster Funeral Homes, Largo Chapel.