A Maine engineer from Colombia, working legally under an H-1B visa, was detained, shackled and held by U.S. Immigration and Customs Enforcement agents for a long day in January during an operation meant to sweep up illegal immigrants in the state for deportation.  ICE released the engineer, Juan Sebastian Carvajal-Muñoz, after 12 hours and now  he is suing the Dept. of Homeland Security and one of the agents who held him for wrongful detention. Carvajal-Muñoz  had studied for a masters degree at the University of Maine before accepting a job involved in bridge soil and foundation analysis at GEI Consultants in Portland, Maine. His detention and lawsuit come in a year when engineering firms face sharply reduced opportunities to fill open positions using the H-1B visa program as the Trump administration limits legal immigration. On the morning of Jan. 22, while driving to work in Portland, ICE agents involved in the sweep stopped Carvajal-Muñoz  and sought identification.…