All seven people on board a Beechcraft air ambulance that crashed in the Indian state of Jharkhand on Monday were killed, officials said on Tuesday, including two crew members, the patient and his relatives.

The Beechcraft C90 plane, operated by Redbird Airways, took off from state capital Ranchi but requested a change to its flight path due to weather, the Directorate General of Civil Aviation said on Monday.

The aircraft subsequently lost communication and radar contact, the regulator said.

“We have pulled out the bodies and sent them for post-mortem and further investigation,” said Keerthishree G, the deputy commissioner of Chatra district, where the crash occurred during a thunderstorm.

A team from India’s Aircraft Accident Investigation Bureau has been dispatched to investigate the cause, the regulator said. Most air crashes are due to a combination of factors and can take at least a year to investigate, according to industry experts.

Relatives of the patient, Sanjay Kumar, told reporters he was injured in a fire and was initially undergoing treatment in Ranchi.

“His condition had become worse so we were taking him to Delhi by air ambulance,” said Vijay Sau, his older brother.

Last month, a Learjet 45 charter aircraft crashed killing all five people on board, including the deputy chief minister of India’s wealthiest state of Maharashtra and two members of his staff.