Por­tuguese of­fi­cials fo­cused Thurs­day on es­tab­lish­ing the caus­es of the crash of a Lis­bon street­car pop­u­lar with tourists that killed 16 peo­ple and in­jured 21, five of them se­ri­ous­ly.

“The city needs an­swers,” Lis­bon May­or Car­los Moedas said in a tele­vised state­ment about Wednes­day’s de­rail­ment.

The down­town street­car, which is known as El­e­vador da Glo­ria and is a ma­jor at­trac­tion for tourists pack­ing the Por­tuguese cap­i­tal dur­ing the sum­mer sea­son, came off the rails dur­ing the evening rush hour. The crum­pled wreck­age was cor­doned off as in­ves­ti­ga­tors sift­ed through the wreck­age, took pho­tographs and pulled up a met­al ca­ble from be­neath the rails that climb one of Lis­bon’s steep hills.